278 NEW YORK STATE MUSEUM 



disk. On the head and upper part of the body, anterior to the 

 tentacles, it is very thin. 



The mantle and body have black markings, which vary in inten- 

 sity on different individuals. 



Digestive system 

 Plates 15, 16 



The esophagus is very short, and has a diameter of about .6 

 mm. It leads into the crop, somewhat abruptly expanding to a 

 width of about 4 mmi and continues essentially in a straight line 

 for nearly three fourths the length of the body, slightly dimin- 

 ishing in diameter. It then contracts, quickly expanding to 

 nearly its former diameter, to form the stomach, continuing for 

 about one fifth the length of the previous part, gradually dimin- 

 ishing in size, then turning abruptly forward and ending in a 

 position nearly parallel to the constricted part. 



The intestine leaves the posterior part of the stomach, and 

 proceeds anteriorly through the digestive gland, where it turns to 

 the left, and, making a broad curve in the gland, again proceeds 

 anteriorly, in contact with the previously described portion for 

 a part of the distance; then, turning to the right, it forms a loop 

 over the retractor muscles, near their origin; aga:in proceeding 

 posteriorly on the dorsal surface of the crop, nearly to the con- 

 strictor of that organ; again abruptly bending forward and con- 

 tinuing in contact with the last described part, passing under the 

 pulmonary chamber, terminating at the anal aperture near the 

 respiratory orifice. 



The latter two convolutions are oblique to the crop and lie on 

 its dorsal part. In nearly all the specimens which I have ex- 

 amined they are empty and flat, even when all the other parts of 

 the intestine are filled with the remains of food. They are very 

 unlike the rest of the intestine in appearance. Their abrupt 

 turning backward and simultaneous decrease in size, and their 

 dissimilarity in appearance to the rest of the intestine are very 

 misleading, and it requires careful dissection to show the contin- 

 uity with the rest of the intestine, as they greatly resemble a 

 cecum. 



