Glandina triincata^ of Say. 417 



Nutritive System. In Helix, Limax, Vaginulus, Achati- 

 na, Bulimus, and nearly all other genera of the pulmoni- 

 ferous Gasteropoda, the buccal organ is almost uniformly 

 either of an ovoidal or spherical shape, its transverse being 

 but little less^than its longitudinal diameter.* In G. trun- 

 cata, it is strikingly contrasted with that of the genera just 

 mentioned by its remarkable size, and the muscular power of 

 the tongue which it encloses. The parietes of the buccal 

 cavity consist of a thin cylindrical muscular sack, slightly 

 curved at its posterior extremity, (fig. 2, a a,) measuring an 

 inch in length, and one fifth of an inch in diameter. The 

 tongue occupies a large portion of the buccal cavity, is carti- 

 laginous, concave above, convex below, and attached to the 

 inferior and posterior surfaces of the cavity, by several very 

 strong and distinct muscles ; its anterior or free portion is 

 buried in part in an excavation on the floor, immediately 

 above which, is the entrance to the oesophagus. The teeth, 

 on the surface of the tongue, are sharp pointed, elongated, 

 and somewhat recurved, arranged in lines " en chevron," the 

 apex being directed backwards. There are no teeth on the 

 median line, corresponding to the axis of the tongue, and in 

 this respect it differs from many of the Pulmoniferous Gastero- 

 poda, in which a range of median symmetrical teeth is gener- 

 ally found to exist. 



The salivary glands, though apparently forming but a single 

 organ, resemble those of the other Pulmonifera, in having a 

 single duct to each, terminating one on either side of the 

 oesophagus at its origin from the mouth, (fig. 2, c c) but 

 diflfers from them, in being so arranged as to form a collar or 

 ring through which the oesophagus passes. 



The oesophagus, (fig. 2, h,) commencing on the upper sur- 

 face of the buccal organ, having passed through the salivary 

 gland, terminates in the stomach on one of its lateral faces. 

 The stomach consists of two portions, a membranous, and 

 muscular, (/ and e. The first or anterior portion, d, is 



* See anatomical descriptioas of the genera Limax, Helix, and Tebennophorus. 



46 



