1892.] 



MUSCULAR ANATOMY OF AULACODUS. 



525 



SO, too, is the Semi-membranosus in having two distinct parts ; there 

 is, however, too little known at present about the musculature of the 

 Rodentia to allow of any detailed comparisons of Aulacodus with 

 other types. I content myself therefore with pointing out the 

 above-mentioned diiferences from its near ally Gapromys. 



II. Visceral Anatomy. 



As I have already mentioned, Prof. Garrod has described the 

 main points in the visceral anatomy of this Rodent ; I may, however, 

 call attention to a few matters which he did not specially dwell 

 upon. 



The accompanying drawing (fig. 1) illustrates the ridges upon 



Palate of Aulacodus, to illustrate the ridges upon the hard palate. 



the hard palate ; these ridges, as will be seen from the figure, are 

 symmetrica], and at the same time few in number ; they are for 

 the most part in front of the molars. An inspection of the figure 

 will save the necessity for any further description. 



The Spleen is of a triangular form ; its longest diameter measures 

 2| inches, the shorter diameter 1| inches. The Gcecum has been 

 very fully treated of by Garrod ; but he was in error, as I have 

 already pointed out in a previous paper, in ascribing a unique 

 character to the structure of this part of the aUmentary canal : in 

 Bolichotis there are a series of folds in the interior of the caecum 

 whicli bear not a little resemblance to those of Aulacodus. Garrod 

 has also said nothing about the folds of mesentery which support 

 the caecum ; near to the caecum the small intestine has a mesentery 



Prog. Zool. Soc— 1892, No. XXXVI. 36 



