76 Transactions. 



stomach forms the gizzard {gz), which consists of two globular and sym- 

 metrical muscular projections separated by a muscular girdle. If the 

 stomach be opened and its wall examined, two folds of the epithelium in 

 the form of a pad will be seen on its floor, one behind the entrance to the 

 gizzard and the other just in front of it. From each of these two pads a 

 white wavy fold runs along the floor of the stomach towards the intestine. 

 Another wavy fold is present to the right of these two. 



The stomach passes into the intestine {int), which, after running under- 

 neath the aorta on the left side of .the body, crosses the median line and 

 then forms the intestinal coil. The intestine is very long, measuring in some 

 specimens 8| in. when uncoiled. It is coiled round and round the albumen- 

 gland (ag) in a double spiral, the total number of complete coils being eight, 

 only five of which are visible on the surface. It coils four times from right 

 to left, the fourth coil crossing the middle of the albumen-gland trans- 

 versely. After coiling four times in the opposite direction it runs along the 

 right side of the first coil and passes into the rectum. The coils from left 

 to right alternate with those from right to left. The rectum (r) runs along 

 the right side of the body, and opens by the anus into the triangular 

 groove already mentioned. 



The extremely long coiled intestine is characteristic of herbivorous 

 gasteropods. Amphihola has to pass through its alimentary canal enormous 

 quantities of mud in order to obtain the vegetable matter it requires. 

 Examination of the contents of the stomach and the mud itself shows that 

 the food consists principally of diatoms. Several difierent kinds were 

 found, the most frequent being Navicula. The faeces are deposited in long 

 circular strings. 



Hutton's drawing (1879) of the gizzard and stomach is not quite correct ; 

 and he says there are only five coils in the intestine, all reversed. He 

 draws the triangular groove into which the anus opens as if it formed part 

 of the wall of the rectum itself. 



The digestive gland (fig. 3, dgl) is very large, occupying together with 

 the gonad the hinder end of the body, and extending from the region of 

 the stomach up to the apex of the visceral spire. It occupies the median 

 portion of the spire, and lobes extend to the edge alternating with those 

 of the gonad. It is a much-lobed gland, dark brown in colour, and when 

 examined fresh it is seen to be dotted with numerous brown specks, the 

 so-called entochlorophyll granules. 



The duct of the liver, which appears to be single, opens into the right 

 limb of the stomach, near its anterior end (Id). 



The cells lining the lumen of the liver are long columnar cells, but they 

 are of varying lengths, some extending a considerable distance into the 

 cavity, others being very short. Two kinds of cells are distinguishable, 

 (a.) Liver cells : The large cells mentioned above, as well as smaller liver 

 cells, contain small granules, which give the yellowish-green colour to the 

 fresh liver. They stain pink in eosin. (b.) Ferment cells : These occur in 

 amongst the liver cells, and each has a large cavity containing a yellowish- 

 brown granule. These entochlorophyll granules can be seen at various 

 stages of formation, some cells containing minute granules, others granules 

 a little larger, others again very large granules. I tried several tests for 

 these granules, with the following results : They turned red when treated 

 with gentian violet, turned pale green when treated with methyl green, 

 remained brown when treated with osmic acid, and turned dark green when 

 treated with eosin. Acetic acid had no effect ; but they dissolved in caustic 

 potash. 



