236 



Chondrop 



terygii. 



Cyclos- 



tomi. 



ICHTHYOLOGY. 



Raia aquila, or eagle ray, grows to an immense size : 

 it has a projecting parabolic snout : the plates or teeth in 

 the middle of the jaws are in a single row, much broader 

 than long ; but the lateral ones are hexagons in three 

 ranges. The eyes are prominent, the tail very long and 

 slender. It has been known to measure fifteen feet in 

 length, and to weigh 300 lbs. It is said to swim with a 

 slow sailing motion, and when captured vibrates its tail 

 with great activity. It yields much fine oil. Inhabits the 

 Mediterranean, the Atlantic, and Indian Oceans. To this 

 division also we must refer the following species : 



R. guttata, Shaw, Plate CCCVII. fig. 10, synonymous 

 with the Eel- Tenhee of Russel ; R. fasciata, Shaw ; Myl. 

 bovina, and Myl. marginaia, Geoff. ; which last has the snout 

 cleft into two short lobes, and belongs to the sub-genus 

 Rhirwptera of Kuhl. 



Genus Cephaloptera, Dum. The last division of the 

 rays is distinguished by the bifurcation of the appendages 

 to the head, derived from the pectorals, which give the 

 species the appearance of being horned. The head is trun- 

 cated between these projections ; the teeth are less strong 

 than those of Pastinaca, and are finely crenulated on the 

 edges ; the tail, spine, and small dorsal fin, resemble those 

 of Myliohatis. ; 



The best known is the gigantic Chephal. giorna of the 

 Mediterranean, the back of which is blackish, bordered 

 with violet. (PlateCCCVII.fig.il.) The animals which 

 are mentioned by Shaw as Raia manatia, R. fahroniana, 

 and R. Banksiana, are considered by Cuvier as doubtful 

 species.' It is probable that the R. diabolus of Willughby, 

 described by Duhamel, and said also to occur at the Azores, 

 may be a distinct species, or perhaps the same as the Ere- 

 goodoo-Tenkee of Russel, which Cuvier is disposed to con- 

 sider as a species well established. Ch. massena of Risso 

 is a Mediterranean species, twelve feet long and twenty- 

 seven in circumference. The female weighs 1250 lbs., the 

 male about 800 lbs. Top of the horns black, the base blu- 

 ish externally, and white on their inner sides. Of the pair 

 described by Risso, the female was first taken ; and the au- 

 thor adds, that the male continued constantly about the 

 boat for three days, as if bewailing the fate of his compa- 

 nion, and was then found floating dead. 



FAMILY II.— CYCLOSTOMI, OR SUCKERS. 



The suckers, as far as their skeleton is concerned, are the 

 most imperfect of all vertebrate animals. The bodies of 

 all their vertebra; are traversed by a single tendinous cord, 

 uniformly tapering from head to tail, which almost reduces 



the vertebrae to cartilaginous rings, scarcely distinct from Chondrop." 

 one another, and not even cartilaginous through their terygii. 

 whole circumference. The body is terminated abruptly Cycles- 

 in front by a fleshy circular or semicircular mouth, sup- ^ °'°'' 

 ported on a cartilaginous ring formed by the union of the ^^'^~'-^ 

 palatal and maxillary bones. No ribs are distinguishable : 

 there are no solid branchial arches ; but the small branchial 

 rays, scarcely recognisable in Squaltis and Raia, are in them 

 fully developed, and united together into a sort of lattice. 

 The gills, instead of the pectinated form they have in 

 almost all other fishes, exhibit the appearance of little 

 sacs, from the union of each gill with that adjacent. The 

 labyrinth is enclosed in the cranium, the nostrils have only 

 a single aperture, in front of which is a cul-de-sac, mistaken 

 by some authors for a temporal orifice. The intestine is 

 straight and narrow, with a spiral valve. 



Genus Petromyzon, Linn. This genus is distinguish- 

 ed by seven branchial apertures on each side ; the skin 

 above and below the tail is elevated in a rayless fin. The 

 sub-genera are the following : 



Genus Petromyzon, Dum. or Lamprey properly so 

 called. Maxillary ring armed with strong teeth, within which 

 are tubercles, with a hard enamel lining the lips. This ring is 

 suspended by a piece answering to an inter-maxillary bone. 

 The tongue is furnished with two longitudinal ranges of 

 small teeth, and is capable of vigorous motion. The tongue 

 acting like a piston in the circular mouth, is an essential part 

 of the mechanism by which the fish is enabled to attach it- 

 self firmly to stones, or to fasten itself to the larger fishes, 

 which it is thus enabled to suck and devour at its leisure. 

 In respiration, the water is carried from the mouth to the 

 gills by a canal under the gullet, and pierced with lateral 

 apertures. The dorsal fin is farther forward than the anus, 

 and a second unites with the tail. The European species 

 are, 



P. tnarinus, the greater lamprey, which grows to the 

 length of more than three feet. (Plate CCC VIL fig. 12.) 

 It is considered as a delicate food, and is caught as it as- 

 cends rivers in the end of winter and spring.^ Colour yel- 

 lowish, marbled with brown. First dorsal fin very distinct 

 from the second. This fish is common in the Severn, and 

 in the mouths of many European rivers. Its supposed 

 hermaphroditism is mentioned by Sir Everard Home.^ 



P.Jiuviatilis, the lampern, or nine-eyed eel.'' Length from 

 twelve to eighteen inches ; olive back, silvery below ; first 

 dorsal distinct from the second. Two thick teeth, separate, 

 in the top of the maxillary ring. Ascends rivers from the 

 sea ; swarms in the Thames, Severn, and Dee. Vast quan- 

 tities taken in England are sold to the Dutch for the turbot 

 fishery. It abounds in the rivers on the southern side of 



' There is no doubt, however, that one or other of those names refers to an existing though obscurely known species, of enor- 

 mous size. A specimen of the Bankiian ray is said to have been found on the coast of Barbadoes, of such a vast weight that seven 

 yoke of oxen were required to draw it. A figure of tlie Ceph. manatia was sent to Lac^pede, the original of wiiich was alleged to 

 be nearly twenty feet long. " It seems that it is to this species we may refer what Barrere and other travellers have said of the 

 enormous rays of the American and equinoctial seas, which spring above the surface of the water, and splash it to an immense 

 distance on falling into it. Levaillant, in his second voyage to Africa, speaks of having seen one, the smallest of three, which 

 swam round about the vessel, about twenty-five feet long and more than thirty wide; and Sonnini speaks of one which appeared to 

 him larger and wider than the ship in which he was sailing." " Colonel Hamilton Smith once witnessed the destruction of a soldier 

 by one of these Cephalopteri, off Trinidad. It was supposed that the soldier, being a good swimmer, was attempting to desert from 

 the ship, which lay at anchor in the entrance of the Bocca del Toro. The circumstance occurred soon after daylight ; and the man, 

 being alarmed by the call of a sailor in the main cross-trees, endeavoured to return to the vessel ; but the monster threw one of his 

 fins over him, and carried him down. The colonel is positive as to this fish being a Cephalopterus." (Griffith's Anivial Kingdom, 

 vol. X. p. G53.) 



^ The death of Henry I. was attributed to a too plentiful meal of lampreys. They seem, however, to have continued in high 

 esteem in spite of that " untoward event ;" — at least we find Henry IV. granting protection to such ships as brought over lampreys 

 for his royal consorVs table ; and his successor issued a warrant to William of Nantes, for supplying himself and his army with these 

 fishes, wherever they might happen to march. {Rynier, ix. 544, as quoted by Pennant.) 



3 Phil. Trans. 1815, 266. 



•* " Whether," says Sir Thomas Brown, " Lampries have nine eyes, as is received, we durst refer it unto Polyphemus himself, 

 who had but one to judge it ; an error concerning eyes, occasioned by the error of eyes, deduced from the appearance of divers cavi. 

 ties or holes on either side, which some call eyes that carelessly behold them ; and is not only refutable by experience, but also re- 

 pugnant unto reason." (jPscudodoxia Epidemica.) 



