78 GRIFFIN. 



liver. The hepatic duct opens into the stomach by a large 

 aperture on the dorsal side (fig. 21, Plate IV). Projecting 

 from the inner surface of the stomach are numerous, slender, 

 sharp-pointed spines of the same composition and structure as 

 the plates of the gizzard, and arranged in a definite and constant 

 manner (fig. 13, Plate III) . They pass in two rows completely 

 around the stomach, the first row being close to, and paralled 

 with, the posterior margin of the gizzard. The plane of the sec- 

 ond ring is perpendicular to the axis of the stomach. Therefore, 

 it lies about 5 millimeters behind the first ring on the dorsal side 

 of the stomach, but 15 millimeters behind it ventrally. Where 

 the rows approach each other dorsad, they are connected by 

 a short broad band of similar spines. The bands of epithelium 

 on which the spines stand appear to be somewhat modified, 

 being slightly lighter in color and smoother than the remainder 

 of the stomach epithelium. The aperture of the hepatic duct lies 

 directly behind the median dorsal band of spines. It is large, 

 but is guarded by what appears to be an efficient, although pecul- 

 iar, device (figs. 13 and 14, Plate III). At the anterior edge 

 of the aperture stands a large conical stomach plate, which is 

 inclined backward over the aperture. As this plate stands close 

 to the posterior end of the short dorsal band of spines, it may 

 possibly be considered as the hindmost and most developed one 

 of the same series. It differs from plates of similar size in the 

 gizzard in presenting no angles, its base being oval in outline. 

 To the right and left of the aperture is a pair of prominent pad- 

 like structures with much-folded mucous membrane. The meet- 

 ing of the two pads and the anterior plate effectually closes the 

 aperture of the hepatic duct. 



The pylorus is constricted by a weak sphincter muscle. The 

 character of the mucous membrane does not change at the py- 

 lorus, but appears to be the same in the upper part of the intes- 

 tine as in the stomach. The long intestine traverses the length 

 of the liver three times, beside coiling around it, and making a 

 double loop over the surface of the hermaphrodite gland (fig. 

 12, Plate III). Within 15 millimeters of the anus, a sudden 

 change occurs in the nature of the mucous membrane, which 

 there becomes thicker and is thrown into from 10 to 12 longi- 

 tudinal folds. Each fold corresponds to one of the points on 

 the edge of the anal papilla. The rectum occupies the center 

 of the anal papilla ; around it is a considerable thickness of gauzy 

 connective tissue, crossed by numerous radiating fibers connect- 

 ing the rectum and the dermis. 



