422 



MUSEUM OF ANIMATED NATURE. 



[AcALEPUiE. 



The Ciliosrrada, or Ciliograde Acalephte, next 

 demand our' notice. These are transparent gelati- 

 nous animals, spread throughout all neas, and raov- 

 insf by the agitation of myriads of minute cilia with 

 which they are provided. It is on thi» circumstance 

 chiefly that the groups agree, lor in external form 

 they jn-eatly differ from each other. In Beroe we 

 have a j^lobular or oblon? body with eight longitu- 

 dinal ridges, upon which are attached a set of little 

 cilia, which work with great rapidity, and produce 

 currents m the circumambient fluid. Fig. 3H7C re- 

 presents the Beroe ovata. It is found in the seas 

 of the West Indies. The form of the body is oval ; 

 it is hollow internally and open at the larger end ; 

 its structure is firm, gelatmous, and transparent, 

 and it contracts and expands with great facility. 

 When swimming it is always open and expanded, 

 and the cilia work with the gi-eatest celerity in either 

 direction. " It is impossible," says Browne (Ja- 

 maica), "to express the liveliness of the motion of 

 these delicate organs, or the beautiful variety of 

 colours that rise from them while they play to and 

 fro in the rays of the sun ; nor is it more easy to 

 express the speed and regularity with which the 

 motions succeed each other, from one end of the rays 

 to the other." 



In the genus Cydippe, of which Cydippe pileus 

 is an example, the cilia are composite, and so ar- 

 ranged side by side as to form eight belts of paddle- 

 wheels ; each paddle-wheel consists of a number of 

 cilia placed side by side like the barbs on a feather. 

 The separate cilia, according to Dr. Grant, are 

 tubular, and under the arches which support them 

 are tubes containing a fluid for filling tiiem. But 

 besides these cilia the Cydippe pileus is furnished 

 with two long slender filamentous tentacula, beset 

 with highly sensitive and delicate fibrils ; these 

 tentacles and their fibrils are thrown into spiral 

 coils on the slightest touch, or withdrawn into the 

 body. 



We may here notice a genus termed Callianira, 

 established by P6ron and Lesueur, and which is 

 probably allied to Beroe. The body is regular, 

 gelatinous, hyaline, cylindrical, elongated, tubular, 

 obtuse at the two extremities, and provided with 

 two pair of wing-shaped appendages which develop 

 themselves in large foliations, and are fringed with 

 a double row of vibratory cilia on their edges, 

 and furnished with a pair of tentaculiform appen- 

 dages, and not ciliiited. At one extremity there 

 is a large transverse opening, and probably another, 

 but smaller, at the opposite extremity. Fig. 3877 

 represents Callianira triploptera: locality doubtful. 



In another very remarkable animal, the Cestum 

 Veneris, or Girdle of Venus, we are presented with 

 a very different form, viz., that of a long riband 

 measuring five or six feet in length ; the upper 

 and lower margin are furnished with a double row 

 of cilia, of varying and most brilliant tints, and 

 luminous during the night with phosphorescent 

 lustre. This resplendent creature has been ob- 

 served in the Mediterranean, but appears to be 

 extremely rare. The alimentary canal crosses the 

 breadth of the middle of the riband, the mouth 

 being situated below ; from the digestive apparatus 

 nutritive tubes are given off, and follow each row 

 of cilia, while another tube mns along the median 

 portion of the riband from end to end. Fig. 3878 

 represents the Cestum Veneris, of which we know 

 nothing, except from Lesueur's account and some 

 details communicated by M. Martens of the Russian 

 expedition round the worid to M. de Blainville. 

 " The Physograda, or Physograde Acalephae, con- 

 stitute a singular group of animals, which float in 

 the water either by means of a set of vesicles dis- 

 tended with air, or the body itself, as in the instance 

 of the Portuguese Man-of-war, assumes a vesicular 

 form, capable, it has been said, of being inflated and 

 emptied at will, the animal sinking when the air is 

 expelled ; 'an assertion, however, which is erroneous. 

 What the nature of the air in these vesicles is has 

 not been determined ; it appears to be a secretion 

 furnished by the animal itself, and not taken in from 

 the atmosphere. 



Few marine animals of the present class are more 

 interesting to the voyager as he crosses the tropical 

 seas than the Portuguese Man-of-war (Physalia pe- 

 lagica). Tinted with blue, green, and crimson, 

 shoals of these creatures float past the vessel glit- 

 tering in the sunbeams as the current carries them 

 onwards. The Physalia consists of an oblonir air- 

 vessel surmounted by a fringed crest or sail. From 

 the under portion of the air-vessel hangs down a 

 group of tentacula of three kinds: first, an anterior 

 cluster of short tubular filaments tufted in their 

 pedicles; secondly, a number of long filaments 

 varying in extent ; and thirdly, a set of still longer 

 tentacles, having a thick and firm base, atid mus- 

 cular fibres continued along their course : "The 

 longest of these ap|)endages," according to Mr. G. 

 Bennett, " are used by the Physalia for the capture 

 of its prey, and are capable of being coiled up 

 within half an inch of the air-bladder, and then I 



darted out with astonishing rapidity to the distance 

 of twelve or eighteen feet ; twining round and 

 paralyzing by means of an acrid secretion any small 

 fish within that distance. The food thus seized by 

 the tentacula is rapidly conveyed to the short ap- 

 ])endages or tubes, which are furnished with mouths 

 for its reception. These tubes appear to constitute 

 the stomach of the animal, lor upon a careful dis- 

 section nothing like a common receptacle for food 

 could be observed, nor could Mr. Bennett defect 

 any communications between them and the air- 

 bladder, to the inferior portion of which they are 

 attached by means of a dense muscular band. 

 After an examination of an immense number of 

 specimens, Mr. Bennett was unable to discover the 

 orifice usually stated to exist at the pointed end of 

 the bladder, nor could he ever succeed in expelling 

 any portion of the contained air without a puncture 

 being previously made. This organ consists of two 

 coats, the outer of which is dense and muscular, 

 readily separating from the inner, which resembles 

 cellular membrane. 



The ]):u'tial expulsion of air from the bladder did 

 not at all affect the buoyancy, or appear in any way 

 to incommode the Physalia; and even when it had 

 completely collapsed the animal still floated on the 

 surface. Upon removing the bladder entirely, the 

 mass of tentacula sank to the bottom of the vessel, 

 and though their vitality remained, all power of 

 action was entirely destroyed." (' Proceeds. Zool. 

 Soc' 1837, p. 43.) 



The tentacles are very irritable, and the secretion 

 which exudes from this produces on the hand they 

 touch extreme pain and inflammation. Mr. G. 

 Bennett thus describes what he suffered on being 

 stung on two of his fingers: — "The sensation was 

 similar at first to that produced by a nettle, but 

 before a few minutes had elapsed a violent aching 

 pain succeeded, affecting more severely the joints 

 of the fingers, the stinging sensation at the same 

 time continuing in the part fii-st touched by the 

 acrid fluid. On cold water being applied with the 

 intention of removing or lessening the pain, it wrs 

 found rather to increase than diminish the effects. 

 The irritation resulting from the poisonous fluid 

 extended upwards, increasing in severity, appa- 

 rently acting along the course of the nerves, and in 

 the space of a quarter of an hour the effect in the 

 fore-arm was very violent, and at the elbow-joint 

 still more so. It may be worthy of remark that 

 when the joints became affected the pain always 

 increased. It became at last almost unbearable, 

 and was miu-h heightened on the affected arm 

 being moved. The pulse of that arm was also 

 much accelerated, and an unnatural heat was felt 

 over its whole surface. The pain extended to the 

 shoulder-joint, and on the pectoral muscle becoming 

 attacked by the same painful sensation, an oppres- 

 sion of breathing was occasioned, and proved very 

 distressing. The continuance of the pain was very 

 severe for nearly half an hour, after which it gradu- 

 ally abated ; but the after effects were felt during 

 the remainder of the day in a slight degree of 

 numbness and increased temperature of the arm. 

 About two hours after I had been stung I perceived 

 that a vesicle (blister) had risen on the spot." 



The tentacles of the Physalia are of a beautiful 

 purple with a mixture of crimson, and have a pe- 

 culiar odour. The crest or sail is irritable as well 

 as the tentacles, and expands or contracts under 

 varying circumstances. It is of a blue colour with 

 streaks of sea-green blended with rich crimson. 

 After death the exquisite colours of this animal, 

 which render it so attractive to the eye, gradually 

 fade away. 



During rough weather numbers of Physaliae are 

 often thrown on the beach, where they are found 

 with the air-bladder still inflated, a sufficient proof 

 the animal has no power of getting rid of the air 

 and then sinking for safety. Though the Physalia 

 is principally to be seen in the tropical seas, it 

 occasionally visits the shores of our island in con- 

 siderable numbers, which, in loose companies, are 

 carried along, passively yielding to the current or 

 the breeze. 



Fig. 3879 represents the Physalia pelagica 

 (Physalus pelagicus, Lamarck ; Physalia Arethnsa, 

 IBrowne). The crest is retracted, and only just 

 appears. 



Of species in which the swimming organs are 

 complex and vesicular, we may turn to the following 

 strange beings, of which mere description will con- 

 vey a very inadequate idea, and indeed respecting 

 which much remains to be known. 



Fig. 3880 represents — A, Rhizophysa filiformis, a 

 slender transparent fililbrm species, with an air blad- 

 der at one extremity : B, Physsophora Muzonema, 

 in which there are two series of vesicular bodies, to 

 which are appended numerous diverse cirrhiform 

 productions or tentacula. 



Fig. 3881 represents a portion of Apolemia 

 Urania : a, a part still more highly magnified ; b, a 

 single sucker. In this genus the body is greatly 



elongated, cylindrical, and vermiform, provided an- 

 teriorly with many natatory organs in two rows ; 

 and behind with solid s<iuamous organs, between 

 which come forth tentaculiform cirrhi furnished with 

 vermiform suckers. 



Fig. 3882 represents Protomedea lutea: the body 

 is long, and furnished above with an imbricated as- 

 semblage of gelatinous bodies in two alternate rows ; 

 from the base of this imbricated float hang filament- 

 ous tentacles with cirrhi. 



Fig. 3883 represents Hhodophysa helianthus. In 

 this form the body is short and cylindrical, swollen 

 above into an air-bladder, and provided below with 

 a variable number of petal-like gelatinous bodies 

 and tentaculiform cirrhi. 



The Cirrhigrada, or CirHiigrade Acalephae, may 

 now be noticed. In the animals of this group we 

 find an internal delicate calcai°eous or cartilagi- 

 nous support, forming a sort of skeleton or axis. 

 The Cirrhigrada move in the water by means of 

 cirrhi or tentaculiform appendages numerously dis- 

 posed on the under surface; and some, as the Velella, 

 have an elevated membrane or sail on the upper 

 surface. 



In Velella the body is membranous, oval, very 

 much depressed, convex above, showing a trans- 

 parent, oval, cartilaginous, dorsal shield, marked 

 with concentric striaa, and surmounted by a vertical 

 and oblique crest of a delicate semicartilaginous 

 structure, which acts as a sail, and aids the cirrhi. 

 Below the body is concave, with a central probosci- 

 diform mouth, surrounded by numerous tentacular 

 cirrhi, those which are most external being the 

 longest. Several species appear to exist in the warmer 

 seas. Fig. 3884 represents the Velella lata: a, the 

 upper surface, showing the dorsal shield and crest ; 

 b, the under surface, showing the mouth and ten- 

 tacles. The colour of these creatures is a fine 

 blue, and as shoals float along, often of great ex- 

 tent and in compact order, they present an inter- 

 esting spectacle. They are found in the seas of 

 Europe, Asia, Australasia, and America. Velella; 

 are occasionally washed upon our shores during 

 storms. 



Closely allied to Velella is the genus Rutaria, in 

 which the body is oval or circular, and sustained 

 by a subcartilaginous, compressed, elevated piece, 

 with a muscular, moveable, longitudinal crest 

 above; the under surface is concave, with a cen- 

 tral proboscidiform stomach surrounded by a single 

 row of marginal tentacula. The species known 

 are very small, and transparent. Fig. 3885 repre- 

 sents Rataria mitrata, greatly magnified. May not 

 some of the species be the young of Velella ? 



Another genus is Poipita. The body of the ani- 

 mals of this genus is flat and circular, and the outer 

 membranous tissue invests a cartilaginous circular 

 plate, concentrically striated, and also in a radiat- 

 ing direction. This plate is extremely light and 

 jiorous, and acts as a sort of float. The body is 

 somewhat concave below, and furnished with a vast 

 number of tentacula, of which the outermost are the 

 longest, and furnished besides with small cilia, each 

 terminated by a globule ; the inner tentacles are 

 simple ; the mouth is central and proboscidiform, 

 and conducts to a simple stomach imbedded in 

 what appears to be a glandular mass. The creatures 

 are of a most beautiful blue, and are common in the 

 Mediterranean and the warmer seas. 



Fig. 3886 represents Porpita gigantea : a, the up- 

 per surface ; h, the under surface. 



Fig. 3887 represents Porpita glandifera, in profile. 

 From the genus Porpita have been separated some 

 species, forming the genus Polybrachionia of 

 Guilding. The tentacles are extremely numerous, 

 and the dorsal disc vitreous. Fig. 3888 repiesents 

 the Polybrachionia Linnaeana, enlarged : a, the up- 

 per side ; b, the lower side. This species is very 

 beautiful, and may be seen in calm weather float- 

 ing on the tranquil surface of the Caribbean Sea. ahd 

 ever and anon entwining its arms with great address 

 and promptitude around its prey. The body is azure 

 blue, the tentacles of a pallid tint. This animal is 

 probably the Porpita cscrulea of Eschscholtz. 



The Diphyida (Dyiphydes or Diphydie), to which 

 we now invite attention, constitute a strange group 

 of marine creatures, the nature of which is en- 

 veloped in much obscurity. In geneial the body 

 consists of two distinct portions or individuals, one 

 of which, viz., the jiosferior, is fitted into a cavity or 

 hollow receptacle of the other, or anterior portion; 

 but so slight is the union between them, that they fall 

 asunder on the merest touch. These two parts are 

 more or less dissimilar in form ; and from the root of 

 the nucleus of the receiving or anterior individual 

 emerges a long ciiThifoim appendage prolonged more 

 or less backwartls. The structure is subcarlilaginous 

 and transparent, and in both portions is ordinarily to 

 be seen a cavity more or less lunnel-shaped.Ojjening 

 externally by a wide and regular, though diversi- 

 form aperture. It is by the alternate coiitracti<.n and 

 dilatation of these cavities, the water at each con- 

 traction being smartly thrown out, that the animal is 



