1882.] 



ANATOMY OF ERETHIZON DORSATUS. 



277 



of the caecum which is opposite the entrance of the ileum. This band 

 is much more marked on tlie colon of Hijstrix cristata than on that 

 of Uret/iizon. There is the normal ileo-csecal valve, and besides 

 this a very remarkable valvular constriction, or circular reduplica- 

 tion (c), at the entrance into the large intestine from the caecum. 

 It is something like the pyloric valve, only less defined, especially 

 on one side|. An essentially similar structure exists in the Guinea- 

 pig, of which I have not met with any description. There is 

 no spiral valve in the caecum, but only a series of constrictions 



Abdominal aspect of the liver of EretUzon dorsatus. 



Letters as before ; and C, caudate lobe ; h.a, hepatic artery ; h.d, hepatic 

 duct, ; f.v, portal vein. 



corresponding to the saccuh formed by the longitudinal bands 

 There are no Peyer's patches ; but there is a chain of glands (sixteen 

 single or in pairs) which extends across from the ileo-csecal valve to 

 the cseco-colic aperture. 



The liver consists of the normal four large lobes, with a small 

 Spigelian and caudate lobe. There was, however, no gall-bladder 

 in the specimen examined. The right segment is much larger than 



' \ preparation showing this structure, made from the specimen here 

 described, has been preserved in the Museum of the Eoyal College of Surgeons. 



