30 



arched form of the head and the large eyes produce in these ani- 

 mals a slight resemblance to young rabbits ; their affinity, however, 

 is with the Muridce." 



Reithrodon typicus. Reithr. vellere supra pilisjlavescenti-fuscis 

 et niffrescentibus i?itermixtis composito ; regione circa oculos, genis 

 lateribusque corporis auratis, pilis pallide fmcis int^rmixtis ; 

 partibus inferioribus auratis ; rhinario ad latera Jiavescenti- 

 albo ; auribus magnis, intus pilis Jlavis, extiis flavis et fuscis, 

 indutis ; caudd supra pallide fused, subtits sordide alba ; pedi- 

 bus albis. 



unc. lin. 

 Longitudo ab apice rostri usque ad caudse basin 6 



• ab apice rostri ad marginem oculi . 8^ 



ab apice rostri ad basin auris .... 1 4^ 



tarsi digitorumque 1 2J 



auris S% 



Latitude auris B\ 



Hab. Maldonado. 



Reithrodon cuniculoides. Reithr. supra griseus, flavo-lavatus, 

 pilis nigris intennixtis ; abdoniine guldque pallide Jlavis ; nati- 

 biis albis; pedibus albis; auribus mediocribus, intus pilis flavis, 

 extiis pilis pallide Jlavis, obsitis, maculd nigrescente ad mar- 

 ginem aiiteriorem positd ; pone aures, notd magna albescenli- 

 jlavd J caudd corpore breviore, supra pallide fused, subtiis alba. 



unc. lin. 

 Longitudo ab apice rostri usque ad caudae basin 6 5 



caudae 3 3^ 



' ab apice rostri ad marginem oculi . 9^ 



ab apice rostri ad basin auris .... 1 4 



tarsi digitorumque 1 4^ 



■ auris 7 



Hab. Santa Cruz. 



In conclusion, two other new Rodents were characterized under 

 the generic name of 



Abrocoma.* 



Dentes primores f acuti, eradicati, anticfe laeves : molares utrinque 

 \ subsequales, illis maxillae superioris in areas duas transver- 

 sales ob pllcas vitreas acutfe indentatas divisis ; plicis utriusque 

 lateris vix sequfe profundis ; illis mandibulse inferioris in tres 

 partes divisis, plicis vitreis bis intemfe, semel extern^ indenta- 

 tis, area prima sagittse cuspidem fingente, caeteris acut^ trian- 

 gularibus. 



Artus subsequales. 



Antipedes 4-dactyli, extemo brevissimo, intermediis longissimis et 

 fer^ aequalibus. 



* ' A/ipos, soft; KojU)i, hair. 



