102 Mr. 0. Thomas OM 



type, l)ut that is a very ohl spcciiueti. Their bulhe are all 

 smaller than in the type o£ G. cachintis, and about the same 

 as in O. lockwoodi. 



11. Ahodoii simula/or, Thos. 



cJ. 545, 550, 551, 555, 557, 500, 5G8, 570, 571, 571, 576, 

 r>9:\, 596, 603, 605, 008 ; ? . 552, 55^, 551>, 509, 575, 581, 

 588,590,501,594,609. Jujny. 1258 m. 



c?. 020, 6?>2, 650, 658, 6G0, 662; ?. 612,641. Villa 

 Carolina. 500 m. 



This fine series, of all ages, shows, firstly, that A. slmn- 

 lator is much more hypsodont than ordinary Akodons of the 

 aretiicola group, being, in fact, intermediate between the 

 latter and the extremely hypsodont Ili/psimt/s. And the 

 same is no doubt the case with the other large Akodons of 

 the present group, most o£ which arc known only by more 

 insufficient material, often with greatly worn teeth. Degrees 

 of hypsodontism are always very difficult to judge without 

 specimens of many dilTerent ages; so that this series is of 

 special value. 



Secondl}^ I would note tliat A, siimilator proves to be more 

 variable in colour than usual, some specimens being, like the 

 original set, gre}- anteriorly and butily posteriori}', others with 

 the buffy covering the whole l)ody, and others, again, nearly 

 uniformly brown. These ditferences are not local, and no 

 corresponding differences can be found in the skulls. 



12. Akodon sp. (near A. dolores). 



(Villa (Carolina.) 



A skin (no. 656) from V^illa Carolinn, wliich appears to be 

 quite indistinguishable from llesperoniysvemistus^ has assigned 

 to it, but L feel sure wrongly, a skull showing a very close 

 resemblance to that of the Cordova Akodon dolores, an auim;d 

 with no external similarity to the Ilesperomys, and belonging 

 to yet another group of Akodon. No skin in the collection 

 seems suitable tor this skull, wliich must remain undetermini'd 

 until lurtlier collections are made. ^1. (/(>/o/-e.s- is not specially 

 hypsodont, as ;u(» A. simulatov aiul acnosus, nor are the in- 

 cisors proodont, as is the case with A. lacteus and orbus, from 

 Leon, Jujny, and 01 ro Cerro, Catamaicn, rospectivel}'. 



\',\. Akodon conosiiSy Thos. 



(J . 580, 5S5, 589, 592, 595, GOO ; V • 505, 500, 583. 

 Jujuy. 1258 m. 



