154 MR. ST. GEORGE MIVART ON MICRORHYNCHtJS. [Mar. 1 3, 



liar feature is its small head and exceedingly short muzzle, in which 

 it differs remarkably from the other Indrisince, and from the true 

 Lemurs. Fully the "proximal third of the sole of the hind extremity 

 is hairy, and the four outer digits of both the anterior and the 

 posterior extremities are united together by integument as far as the 

 distal ends of the proximal phalanges of the respective digits. The 

 index finger is very short, and the pollex slender and placed far back. 



The dimensions of the skin are : — 



inches. 



Length from muzzle to root of tail 12*7 



of tail 13-0 



from shoulder to extremity of fourth digit of hand 7'5 



from groin to extremity of fourth digit of foot . . 12-0 



from shoulder to root of tail 8'0 



of hand (palm and fourth digit) 2'8 



of foot (sole and fourth digit) 3-5 



Fig. 1. 



Iff §'Wfi^ ," 



5 1" 



Left dental series of both jaws. Scale, twice nat. size. 



As regards the dentition, there are two pairs of upper incisors, which 

 are widely separated from each other. Though the prsemaxilla is 

 very short, yet all the incisors are in front of the canines (thus differ- 

 ing from Hapalemur), and, the inner one of each pair being in front 

 of the outer one, two incisors are visible when the skull is viewed in 

 profile. The posterior one of each pair is very considerably larger 

 than the more anterior one — a condition which obtains in no other 

 genus of the order, and which presents a marked contrast to the pro- 

 portions existing in Indris and Propithecus*. 



The upper canine is very peculiar, and much resembles the tooth 

 immediately behind it. It is the most vertically extended tooth in 

 the upper jaw, yet but very slightly exceeds the most anterior pre- 

 molar in that or in any dimension f. 



* In De Blainville's figures (pis. 4 & 8) of Indris, the posterior incisor is re- 

 presented as the larger, but not so in pi. 11. Of the specimens in the British 

 Museum, in one the posterior incisors are decidedly the smaller ; in the other 

 they all appear subequal, as they are in the specimen in the College of Surgeons' 

 Museum. In both specimens of Propithecus in the British Museum the ante- 

 rior incisors are the larger. 



t Such is the case in the specimen described, and in the skull figured, by De 

 Blainville (Osteographie, Lemur, pi. 8) ; but in the skull at Leyden the canine 

 is more produced, judging from Prof. Van der Hoeven's figure {toe. cit. pi. 1. 

 fig. 6) and from the woodcut (of the same skull?) in Todd's Cyclopaedia, art. 

 Quadrumana, vol. iv. p. 215. fig. 130. 



