512 transactions liverpool biological society. 

 Mid-Gut. 



The pyloric valves project into the achitinous 

 Mesetlteron or Mid-Cut. This is by far the largest part 

 of the intestine and measures on the average about 

 6 cm. in a well-grown specimen. This great stretch of 

 achitinous gut is the more striking when one examines 

 the allied Eupagurids. The American E. longicarpus 

 has chitin stretching into the anterior part of the 

 abdomen, and in our own E. prideauccii it is found in 

 about the fourth abdominal segment. In the present 

 species the mid-gut does not cease till it joins the rectum 

 in the fifth abdominal segment. At the base of the 

 pyloric ampullae, at the origin of the mid-gut, the two 

 ducts of the digestive gland originate, and immediately 

 behind their point of origin, but on the dorsal surface, 

 arise a pair of pyloric caeca (mid-gut caeca of Pearson). 

 The caeca come off close together and run forward on the 

 top of the stomach for a short distance, closely applied to 

 its walls, and then dip down, passing slightly forwards, 

 till they each end in an irregular coil underneath the 

 stomach. 



The Digestive Gland (or liver) may conveniently be 

 described now. It consists essentially of a pair of axial 

 tubules stretching from their origin under the stomach 

 to a considerable distance into the abdomen, and giving off 

 numerous diverticula (fig. 25). The axial ducts are round 

 and broad in section, and during their passage through 

 the thorax are applied closely to the latero-ventral side 

 of the alimentary canal. The caecal diverticula which 

 arise from this part are few and short, but when the 

 central ducts have passed the peduncle, they separate 

 from the gut and run the remainder of their course on the 

 surface of the flexor muscles of the abdomen. It is from 



