69 



Isodon pilorides, tlie species on wliich ihe generic characters were first 

 pointed out. He further observed thiit the affinity of this genus to 

 Cavia, iiidicateil by Mr. Say from the comparisoii of crania, received 

 corroboration iVoin various partirulais of the anatomy of the animai j 

 an affinity, he conceived, not to be denied on account of the e.\ist- 

 ence in Capromys ofperfect clavicles, and their absence in Cavia; for 

 an anatomical character, he observed, is not the less aitificial if taken 

 without reference to the ręst of the organization. 



" The individual examined vvas a fuUy grown malė, and measured 

 1 foot 6 inches from the end of the nose to the setting on of the tail, 

 the length of the tail being 7į inches. 



" On the abdomen being laid open the viscera were found covered, 

 as in the j4gouti,^\th an extensive omentum, which was loaded vvith 

 lardaceous fat. The sternal layers of the omentum extended along 

 the stomach and spleen across the \vhole of the abdomen; but the 

 dorsal layei-s, vvhich vvere continued from a fold of the colon, extend- 

 ed from the right side only to the mesial line, vvhere they terminated 

 by a free edge without adhering to the sternal layer, and conse- 

 quently left at that part a large orifice by vvhich the fingers could 

 be introduced into the omental bag. The liver, stomach, and spleen, 

 occupied as usual the hypochondriac and epigastric regions, and the 

 gall-bladder was also dislinctly visible lying betvveen tvvo separate 

 lobes and not in a partial fissure at the under surface of the liver. 

 The cacum, a capacious, elongated and sacculated bag, extended, as 

 in the Cavies, from below the stomach dovvn the left side and across 

 the lower part of the abdomen, terminating in the right iliac region 

 with its apex directed tovvards the diaphragm. A long and loosefold of 

 the colon extended obliquely across the abdomen from the right hypo- 

 chondriac to the left iliac region, and the remaining space above 

 the cacum vvas occupied by convolutions of small intestine. In the 

 regio pubis the testes vvere situated, of the large size vvhich seems pe- 

 culiar to this fertile order of Mammalia, v\'ith the globus major of the 

 epididfjmis only projecting through the abdominal ring : these pro- 

 jecting portions vvere about the size of kidney-beans and appear to 

 have been mistaken by M. Desmarest for the tesies themselves, vvhich, 

 hovvever, are rather larger than olives. The abdominal ring is large 

 enough to perniit the whole of the gland to be protruded,, and from 

 the attachment of the inferior fibres of the internal obliąue and trans- 

 Versalis museles to the globus major, and their capability of forrning a 

 cremasteric bag for the testes vvhen these are pushed out of the ab' 

 domėn, it is most probable that they are so protruded, as in other 

 Rodentia, during the rutting season. 



" The stomach is of an oblong shape, pretty equally round«d at 

 both extremities. The cesophagm is narrow, and after a short course 

 in the abdomen terminates at 2 inches 2 lines from the left extre- 

 mity of the stomach ; a pouch of the šame extent is continued from 

 the right of t\ie pylorus, vvhich is situated only lį inch to the right of 

 the cardia. The length of the stomach vvhen distended is 6 inches, 



