BOWERBANKIA. 



BRACK IOPODA. 



63i 



the B. furfuracea, which grows iu great abundance on the heaths near 

 Florence, is collected and sold iu the markets, and, according to 

 Micheli, is an esteemed article of food. 



(Biachoff, ifedicinuch-Phai-maceu'im-he Botanik; Burnett, Outlines 

 of Botany; Association Medical Journal, No. xxii.) 



BOWERBANKIA, a genus of Ascidioid Polypes, or Polyzoa, 

 belonging to the family Vesiculariailit. It was named by Dr. Farre in 

 honour of Mr. J. S. Bowerbank. The following character is given by 

 Dr. Johnston in his ' British Zoophytes : ' Polypidom confervoul, 

 matted or irregularly branched ; the cells sessile, unilateral, irregular; 

 the inflected portion with a spinous or filamentous rim. The polypes 

 ascidian, with ten ciliated tentacula, and a strong gizzard. There is 

 but one British species, B. imlricata. It has ovate or ovato-cyliu- 

 drical cells, which are irregularly scattered on the polypidom in dense 

 clusters. In its young state the polypidom is creeping and matted ; 

 but as it arrives at maturity it becomes arbuscular and erect. From 

 this circumstance several names have been given to this species. It 

 is found growing on the'/'uci and corallines which are exposed at 

 low water, and very generally distributed on the British coast. It 

 grows in profusion on the chains of the steam-ferries at Southampton 

 and Portsmouth. (Johnston, British Zoophyte*.) 

 BOWSTRING-HEMP. [SAXSEVIERA.] 



BRACHE'LYTRA, a division of the order Coleoptera. The insects 

 of this section (which answers to Linnaeus' s genus Stapliylinui) may 

 be distinguished by the elongate form of the body and the shortness 

 of the wing-cases, which in most instances scarcely cover one-third of 

 the length of the abdomen : their maxillae are furnished with only 

 one palpus. The apex of the abdomen is provided with two vesicles, 

 which can be protruded at the will of the animal. 



The habits of the Brachdyira are very various, but the greater 

 number of the species are found in putrid animal or vegetable 

 substances, upon which they feed ; some are carnivorous. The 

 shortness of the wing-cases probably allows of a greater flexibility 

 in the body. 



BRA'CHINUS, a genus of Insects belonging to the order Coleoplera 

 and the section Truncalipennes. Generic characters : Body oblong; 

 head and thorax comparatively narrow, the latter generally somewhat 

 of a truncated heart-shape ; palpi and antenna; rather thick, the 

 terminal joint of the former is slightly thicker than the basal joints, 

 and has its apex truncated ; mentum emargiuate, and furnished with 

 a small tooth-like process in the middle. 



The Brachini possess a remarkable power of violently expelling 

 from the anus a pungent acrid fluid, which, if the species be large, 

 has the power of producing a discoloration of the skin similar to that 

 caused by nitric acid. A loud report, considering the size of the 

 insect, accompanies the expulsion of this fluid, which being dischargee 

 instantly evaporates. 



About five species of the genus Brachinus have been found in this 

 country, of which B. crepitaru in the most common. It is found under 

 stones, and occurs plentifully in chalky districts. This species is 

 rather less than half an inch long ; the head, thorax, and legs are of 

 a yellowish-red colour ; the wing-cases are greenish, or blue-black ; 

 the antennae are reddish, with the third and fourth joints black 

 Many of the species of Brachinut resemble the above in colour. The 

 species of the genus Aptintu (a genus very closely allied and differing 

 chiefly in being apterous) are generally of a yellow colour, having 

 four black spots on the elytra ; the head and thorax are also often 

 more or less suffused with black ; they are likewise of a larger size 

 for the most part, and abound more particularly iu warm climates. 

 BRACHIOBDELLA. [ASSEUDA.] 

 BRACHIONiEA. a family of animals belonging to the order Rotifera 

 It embraces a large number of species formerly included under the 

 genus Brachionvs. It is distinguished from other families of Jtotifera 

 - by the possession of two rotatory organs, and a lorica or shell. The 

 win !{, or rotatory organs, are apparently composed of five parts, three 

 of which are central, and two lateral ; the latter of which alone form 

 the true rotatory organs, the others being only ciliated fronta 

 portions. Some have two setae proceeding from the rotatory apparatus 

 as in Synchata. The jaws are supplied with teeth and four muscles. 

 They are supplied with biliary glands and ovary, male organs, and a 

 contractile vesicle. Ehrenberg regards a red spot in them as indica 

 tive of the presence of a nervous system. 



This family comprises the following genera : Pterodina, Anouretta 

 Brachioniu, Lepadella, L'uchlanu, Dittocharis, Satpina, {Jolme.Ua, 

 Itiiiulut, Polyartkra. 



Ehrenberg makes seventeen genera; but Dujardin has reduced 

 the number to ten, on account of the insignificant characters on 

 which Ehrenbcrg's genera are founded. 



/:, inhianut may be taken as a type of the family, and B. urceolarit 

 f its most characteristic species. The genus Brachionut has 

 a single eye (d), and a furcate foot or tail (i). It has a reddish 

 colour, the shield smooth, with six short spines in front ; the posterior 

 extremity rounded. The jaws have each five teeth. Both male and 

 friii Je organs are present. It is a very common species in both brackish 

 and fresh waters. Dujardin says he has constantly found it in the 

 cisterns of the Jardin des Plantes, in Paris, and especially in thai; in 

 which the aquatic plants grow. A few years ago the waters of the 

 Serpentine, in Hyde Park, swarmed with this species, and it is very 



:onstantly present in the waters supplied to the cisterns of London 

 or drinking purposes. 



Brachiontu urceolaris, highly magnified. 



a, Rotatory cilia ; 4, internal branchial organs ; d, eye ; e, phaiynx and jaws ; 



/, stomach ; g, appendages of stomach ; A, ovary ; t, tail. 



BRACHIONUS. 



BRACHIO'PODA, or Brachiopodom Mollutca, Cuvier's fifth class 

 of Mollusks, the Palliobranchians (Palliobrancliiata of De Blainville), 

 being the first order of De Blainville' s third class of Mollusks 

 (A cfphalophora). 



This class, though comparatively low in the scale of creation, is 

 interesting to the physiologist, and of considerable value to the 

 geologist, who finds in the fossil forms no small portion of those 

 natural medals which indicate the history of the stratification of our 

 globe. Comparatively few of the species exist in the seas of the 

 present day, but in former periods of the earth's surface they occupied 

 the position now taken by the Lamellibranchiate HoUtmca. 



Cuvier, in his anatomy of Linyula anatina, in the 'Annales du 

 Museum," first made known that organisation by which the mantle, 

 in addition to its office of secreting the shelly defence of these 

 bivalves, is made subservient to the circulating system. Instead of 

 the branchiae of the ordinary bivalves he found in the situation usually 

 occupied by them two fringed and spirally-disposed arms, and that the 

 branchiae presented themselves on the internal surface of both lobes 

 of the mantle in oblique parallel lines. He further found that these 

 lobes were traversed by vessels of considerable size, which returned 

 the blood from the organs of respiration, and that these branchial 

 veins terminated in two symmetrical systemic hearts. Here was a 

 new type of circulation, and to the mollusks which presented these 

 interesting and important modifications he gave the name at the head 

 of our article, significative of the fringed arms which in this class took 

 the place of the foot or organ of progression in the cockle, &c. 



Lamanou and Walsh had previously taken the analogous parts of 

 Ttrebratula for branchiae, and Pallas, who is not quoted by Cuvier, 

 describes the arms of Ttrtbratvla with minuteness and accuracy^but 

 considers them as branchiae, and compares them to those of a fish. 



De Blainville, in the ' Dictioiiuaire des Sciences Naturelles," gives 

 an account of the organisation of Tertbratula. But both Cuvier and 

 De Blainville were led into error in their attempts to trace out some 

 parts of the organisation of Tertoratu'a ; and it was reserved for 

 Mr. Owen, in his acute, accurate, and interesting paper 'On the 

 Anatomy of the Braclnopoda of Cuvier, and more especially of the 

 Genera Tercbralula and Orbicula,' published in the 'Transactions of 

 the Zoological Society of London' (vol. i. p. 145), and derived from 

 the dissection of specimens brought to this country by Mr. Cutning 

 and Captain James Ross, R.N., fully to investigate the subject so as to 

 leave little or nothing to be desired upon the subject of the anatomy 

 of Linyula and of the two genera last named. Our limits will not 

 permit us to follow the learned author through his memoir, the whole 

 of which, together with the beautiful illustrations that accompany it, 

 is worthy of the mcwt attentive perusal by the physiologist and 

 zoologist. The following general remarks from Professor Owen's 

 paper illustrate his views. It should be premised that the Brachiopoda 

 are cryptandrous. 



" On comparing together," says Mr. Owen, " the three genera of 

 Brachiopoda above described, we find that although Orbicula, in the 

 muscular structure of its arms and the proportion of the shell occu- 

 pied by its viscera, is intermediate to Linyula and Terebratula, yet 

 that in the structure of its respiratory organs, its simple alimentary 

 canal, and its mode of attachment to foreign bodies, it has a greater 

 affinity to the latter genus. The modifications that can be traced in 

 the organisation of these genera have an evident reference to the 

 different situations which they occupy in the watery element. 

 Linyula, living more commonly near the surface, and sometimes 

 where it would be left exposed by the retreating tide, were it not 

 buried in the sand of the shore, must meet with a greater variety and 

 abundance of animal nutriment than can be found in those abysses iu 

 which TtrebrattUa is destined to reside. Hence its powers of prehen- 

 sion are greater, and Cuvier suspects it may enjoy a species of loco- 

 motion from the superior length of its pedicle. The organisation of 

 its mouth and stomach indicates however that it is confined to food 



