1908.J 



ANTECHINOMYS AND OTHER MARSUPIALS. 



585 



vidgaris Tullbei-g shows a somewhat different state of affairs ; 

 there are two well developed and narrow loops close togethei- 

 which are, however, of nearly the same length. This agrees 

 with a figure given by Mitchell of Xerus cajjensis, and b^' 

 Gegenbaur of Gynomys ludovicianus * , and "VV. A. Forbes (MS.) 

 of Arcfomys 7narmotta. 



Text-fig. 116. 



Part of alimentarj' tract of Sciurus cinerews. 

 a.e.d. Ansa coli dextra. a.c.s. Ansa coli sinistra. Coe. Caecum. O. Omentum. 



One of the Hystricomorph Rodents not figured by I'ullberg 

 is the Vizcacha, Lagostoinv,s trichodactylus. It is stated, 

 however, to resemble Chinchilla in possessing an ansa coli dextra 

 and an ansa paracoicalis^ which however is more free from 

 the csecum than in Chinchilla. 



In the two examples which I have dissected there are 

 difierences from each other, but I am not clear how far — if at 

 all — either of them differs from the example described by 

 Tullberg. In the one, a female, the ansa paraccecalis was a very 

 short, but rather wide loop, totally unlike that figured by 

 Tullberg for Chinchilla. The ansa coli dextra was long and 



* Ver^l. Anat. d. Wirbelthiere. 



