ETJPAGUE.TJS. 513 



this part of the tubes that the bulky mass of branching 

 diverticula which fill the cavity of the abdomen arises. 

 The gonads are usually imbedded in the liver, and the 

 alimentary canal either passes between the two lobes or 

 through the right portion. The tubules are not packed 

 very closely together, and they therefore retain in 

 section their circular outline. The digestive gland is 

 copiously supplied with blood by the superior abdominal 

 artery and its branches. 



The course of the mid-gut is uninterrupted till it 

 joins the rectum. It is a thin-walled smooth tube, 

 without convolutions, through which the faecal matter can 

 be seen. Just before the rectum a long unpaired caecum 

 [caec, fig. 25) arises from its dorsal surface, which passes 

 backwards between the liver tubules to the dorsal surface 

 of the mass, and terminates in a small coil in the third 

 abdominal segment — a little beyond the testis in the 

 male. The caecum seems to be usually longer in the 

 male than in the female. It has been very badly named 

 the " hind- gut caecum,'''' seeing that it arises from the 

 achitinous part of the alimentary canal. There is 

 apparently considerable variation in the place of origin 

 of this unpaired caecum among the Eupagurids, though 

 it is always derived from the mid-gut. It appears 

 to form some index to the extent of the chitinous 

 lining of the hind-gut, as it always comes off at the 

 junction of the two parts. M. T. Thompson describes it 

 in E. longicarpus as passing from the thorax back into 

 the abdomen — the reverse direction of E. bernhardus — 

 and in E. prideauxii it arises in the fourth abdominal 

 segment more than half-way up the abdomen, and is 

 comparatively short. 



