io8 



Invertebrate Zoology. 



gastric muscles. The lobes of the liver, or mesenteric gland, 

 extend laterally until they reach the limits of the shell. 

 Each lobe, as in the lobster, is composed of a multitude of 

 tubules. 



Lying anteriorly to the heart, and extending laterally over 

 the mesenteric gland, are the voluminous sexual organs. 

 The testes appear as a coiled filament, extending from 

 near the lateral walls of the stomach to the lateral angles of 

 the shell. In the region of the pyloric end of the stomach 

 the filament enlarges into a coiled duct, the vas deferens. 

 Expose the green-glands, and trace out their ducts. 



The comparison of the nervous system of the Brachyuran 

 with that of the Macruran (Homarus) will prove most in- 

 teresting. 



Draw the animal as seen from above. 



