Dr Dalton jun. on the Proteus anguinus. 337 



surface of the upper lip, as in Lepidosiren paradoxa. They 

 are continued into a cylindrical membranous canal, something 

 less than a third of an inch long, situated in the thickness of 

 the lip. There is a long row of fine sharp conical teeth in 

 both upper and lower jaw ; and in the upper there is also a 

 second much shorter row, in front of the first. The tongue 

 is erroneously stated by R. Wagner (Comp. Anat., Vertebrata) 

 to be wanting. It is, on the contrary, very easily seen ; about 

 one-eighth of an inch long, but consisting only of mucous 

 membrane and adipose tissue. The animal has the vertical 

 stomach and short intestinal canal of the allied genera. The 

 anus is a longitudinal slit, just behind the junction of the 

 posterior extremities with the body. The liver is a long, 

 lobulated organ, wrapped round the stomach and upper part 

 of the intestinal canal, and extending nearly two-thirds the 

 whole length of the abdominal cavity. The heart, inclosed 

 in a pericardium, is composed of a single auricle and ven- 

 tricle. The arterial trunk arising from the ventricle is par- 

 tially converted into a double canal by an imperfect longi- 

 tudinal partition. It sends off, on each side, three branchial 

 arteries, and the returning branchial veins unite imme- 

 diately below the situation of the heart, to form a single 

 descending aorta. The lungs are simple, elongated, thin 

 membranous sacs, secured by a fold of peritoneum against 

 the posterior abdominal wall, and somewhat un symmetri- 

 cally developed. The left runs down, from its opening into the 

 oesophagus, nearly three-quarters the whole length of the 

 abdominal cavity ; the right but little over one-half the 

 length. The blood globules of this animal have been long 

 known to be remarkable on account of their large size. They 

 can be easily found almost unaltered in the bloodvessels, 

 and particularly in those of the gills, even in. specimens which 

 have been kept for a long time in spirit. They are of a flat- 

 tened oval shape, like those of the frog, with a central, white, 

 granular, roundish nucleus, also somewhat flattened. The 

 length of the globules varied, in the specimen examined, from 

 •0016 to -0023 inch. The breadth is usually -0013, and the 

 thickness -0003. As this last measurement is exactly the 

 diameter of the human blood globule, some estimate may be 



VOL. LV. NO. CX. — OCTOBER 1853. Y 



