256 



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teropoia inhabit fresh waters, but most of 

 them are marine animals : some are formed 

 for crawling, as the snail, the whelk, &c. ; 

 some are more adapted for swimming ; while 

 a few of this class attach themselves to the 

 surface of rocks, scarcely varying their lo- 

 cality, as is the case with the limpet ; this 

 attachment being produced by the adhesion 

 of the muscular disc, or foot, which acts like 

 a sucker, and can at any time be detached 

 by the will of the animal. 



In the work of Mrs. Gray, of the British 

 Museum, on Mollusca, are figures of the 

 animals of most of the genera of Gasteropoda. 

 To this very carefully executed and autho- 

 ritative work, we refer our readers, as well 

 as to the various miscellaneous articles in 

 this work ; such as ACIIATIXA, BULIMUS, 

 SNAIL, &c. 



fossil Gasteropoda. Among the numerous 

 organic remains which exist, none are more 

 extensively diffused throughout the globe, 

 occupying the various geological formations, 

 than fossil univalve shells. It is, indeed, 

 asserted by some of the most experienced 

 geologists, that every fossil turbinated uni- 

 valve of the older beds, from the transition 

 lime to the lias, belongs to the herbivorous 

 genera, which class extends through every 

 stratum in the entire series of geological 

 formations, and still retains its place among 

 the inhabitants of our existing seas : while, 

 on the other hand, the shells of marine car- 

 nivorous univalves are very abundant in the 

 tertiary strata above the chalk, but are rare 

 in the secondary strata from the chalk down- 

 wards to the inferior oolite ; beneath which 

 no trace of them has yet been found. 



GASTEROSTEUS. The name of a genus 

 of Acanthopterygious ftshes. [See STICKLE- 

 BACK.] 



GASTROBRANCHUS. (Gastrobranehus 

 glutinosa}. The HAG. A cartilaginous fish, 

 which in its general appearance bears a near 

 resemblance to the Lampreys, but which in 

 the Systema Naturae of Linnaeus has been 

 considered as belonging to the class Vermes. 

 It is of a dusky bluish cast above, and reddish 

 towards the head and tail ; is from four to 

 six inches long, and is remarkable for its 

 total want of eyes : the mouth, which is 

 situated beneath, is of an oblong form : on 

 each side are two beards or cirri, and on the 

 upper part four ; in front of the top of the 

 head is a small spout-hole, furnished with a 

 valve, by which it can at pleasure be closed : 

 the teeth, which are of an orange-colour, are 

 arranged on each side of the mouth in a 

 double-row, and in the middle of the roof of 

 the mouth is one sharp-pointed and curved 

 tooth. It has no scales, nor any kind of fin 

 but that which forms the tail, the extremity 

 of the body, where it is surrounded by the 

 caudal fin, which is very shallow, being 

 pointed. Beneath the body, from head to 

 tail, runs a double row of equi-distant pores, 

 through which, on pressure, exudes a viscid 

 fluid ; and beneath the body are two spiracles 

 haying apertures communicating with a 

 series of six globular red cells or vesicles on 

 each side of the body. " The manners of 

 this fish are represented as highly singular : 



it is said to enter into the bodies of such fishes 

 as it happens to find on the fishermen's hooks, 

 and which consequently have not the power 

 of escaping its attack, and by gnawing its 

 way tlirough the skin, to devour all the in- 

 ternal parts, leaving only the bones and the 

 skin remaining. Another peculiarity in this 

 animal consists in its uncommonly glutinous 

 nature : if put into a large vessel of sea- water 

 it is said in a very short space to render the 

 whole so glutinous as easily to be drawn out 

 into the form of threads. When taken out 

 of water the Gastrobranehus is said to be in- 

 capable of living more than three or four 

 hours." The species we have been describ- 

 ing is called the Blind Gastrobranehus, and 

 is an inhabitant of the Northern seas. Ano- 

 ther, and a much larger one, called the Dom- 

 beyan Gastrobranehus, from its having been 

 first noticed by M. Dombey, is found in the 

 South American seas. 



GASTROCH^ENA. The name given to a 

 genus of Acephalous Molluscs, found on the 

 coasts of Great Britain and America. They 

 inhabit an equivalve, inequilateral shell, 

 united by a ligament, and having in the in- 

 terior a small spoon-shaped curvature. The 

 Gastrochana penetrates and makes its abode 

 in hard substances ; and seldom exceeds half 

 an inch in length. They are found in the 

 hollows of shells or other marine substances. 



GAVIAL, or GARIAL. An enormous 

 Reptile found in India, to which the name 

 of the GANGETIC CROCODILE (Crocodihis 

 Gangeticus) is sometimes applied ; but the 

 sub -genus termed. Gavial, by Cuvier, is 

 so strikingly distinguished both from the 

 Crocodile of the Nile and the Alligator 

 by the peculiar form of the mouth, that it is 

 hardly possible, even on a cursory view, to 

 confound it with either of them ; the jaws 

 being remarkably long, narrow, and straight, 

 constituting the anterior part or beak, 

 spreading out at its base, and terminating 

 in front, so as to remind the observer of 

 the beak of the Spoonbill. The head, 

 properly so called, has its sides straight 

 and perpendicular, the upper surface being 

 quadrilateral ; and the mandible, instead 

 of being continued from the forehead by a 

 gradual slope, sinks suddenly to follow a 

 straight and nearly horizontal direction. 

 In the general form and colour of the body 

 and limbs it resembles the common Crocodile, 

 but the number of transverse zones or bands 

 formed by the rows of scales on the back, is 

 greater than in that species. The teeth are 

 nearly double the number of those of the 

 Nilotic Crocodile, and are of equal size 

 throughout the whole length o_f the jaws. 

 It is quite as aquatic in its habits as is the 

 African species ; its hind feet fully webbed ; 

 and the crest on the tail, increasing the sur- 

 face by which it strikes the water, is much 

 elevated. This powerful animal frequently 

 attains the length of twenty-five feet ; and, 

 from its strength and ferocity, is truly for- 

 midable. In one respect, however, it is found 

 very serviceable, viz. in devouring the nu- 

 merous dead bodies of men and animals 

 which are committed to the " sacred river," 

 the effluvia arising from which would other- 



