ALIMENTARY CANAL OF SIHENIA. 455 



tion, the left end of which is produced into an elongate obtuse glan- 

 dular pouch, communicating with the gastric cavity by an oblique 

 slit serving for the passage of the secretion. A fold of the lining 

 membrane continued from the right of the cardia partially subdi- 

 vides the cardiac chamber. A pair of oblong, slightly bent, ob- 

 tusely terminated, subpedunculate pouches open near each other 

 into the narrow beginning of the pyloric cavity, which, after a 

 moderate expansion, gradually contracts to the pylorus. 1 



In the Dugong the esophagus, fig. 3o6,/, terminates nearer 

 the left end of the cardiac portion, from the extremity of whicb 



356 



.Stomach of the Dugong. xxvm. 



the glandular pouch, ib. e, projects, but to a less extent and in a 

 more conical form than in the Manatee : its gastric end or base 

 projects into the stomach as a low circular protuberance with an 

 oblique crescentic orifice, which leads to a flattened winding sinus, 

 formed by a broad membrane spirally disposed in about eight or 

 ten turns, having both surfaces covered with the orifices of fol- 



O 



licles ; and their interspaces filled by the cream-like secretion. 2 

 The muscular coat covering the spiral gland is 2 lines thick : 

 but it quickly increases, as it spreads over the cardiac cavity, ib. 

 , to a thickness of 8 lines, again becoming thinner near the 

 pyloric portion. In order to defend the cardiac orifice against 



1 The stomach of the now extinct boreal Wiytina appears from the record left by 

 Steller to have much resembled that in the Manatee: he was struck by its surprising 

 size, ' 6 feet in length and 5 feet in breadth,' distended with masticated sea-weed. 



2 cxvn". p. 30. A peculiar species of Nematoid worm (Ascaris Halicoris, Ow.) was 

 found in this spiral gland. 



