76 PROFESSOR OWEN ON THE AYE-AYE. 



and attachments. There is also a pair of strong ' levatores penis,' arising from the fascia 

 crossing the vena dorsalis, and inserted by a common tendon into the ossiculum penis. 



^12. Comparison of the External Characters and Dentition. 



In deducing the natural affinities of Chiromys from the ordinary zoological or external 

 characters, and commencing by a comparison of its general form and proportions, I find 

 its nearest resemblance to be to the Malmags {Otolicnus, lUig., Oalago, GeoflFr.) amongst 

 the Lemurid(E ; especially to the species called ' Great Galago ' (Otolicnus crassicaudalus) 

 from the south-eastern part of Africa, and to the 'Black Galago' (0. alleni) from 

 Fernando Po. There is the same general character of the pelage, with the long hairy 

 tail, and the same degree of liberation of the limbs from the trunk ; the same breadth 

 of head and large naked ears ; but, in the shortness of the muzzle, the Tarsius, perhaps, 

 more resembles the Chiromys. The proportionate length of the digits of the hand is 

 almost the same ; but the third digit is much more slender in Chiromys. The hallux 

 of the foot has the flat nail as in all the Lemurs, with the strength and opposable 

 position of that member ; but the four unguiculate toes are more nearly of the same 

 length in Chiromys ; and the tarsal segment is as short as in Lichanotus and Lemur 

 proper. Although the muzzle is deeper and less pointed than in the Lemuridce, con- 

 formably with the large bent incisors and their sockets, it is less deep and is much 

 shorter than in any Rodent, in which order the eyes are placed further back, and are 

 lateral, the premaxillaries being larger and longer, and the whole head being com- 

 pressed in the Rodents. The nostrils are more terminal in Chiromys, and are but 

 partially, instead of being wholly lateral as in Rodents. The upper lip is not bifid 

 as in Squirrels, nor curved downward and backward to cover the lower scalpriform 

 teeth as in most Rodents. Although the mouth is less cleft than in the Lemurs, 

 it is more so than in any Rodent of the same size, and the hairs are not extended upon 

 the inner surface of the angle of the mouth. In Tarsius there are fasciculi of few and 

 long vibrissae, from the exterior of the lips and eyebrows, almost as in Chiromys. 



The trunk is broader, less arched, and larger in the chest than in most Rodents ; and 

 the pelage of the Aye-aye has not the uniform, close-set, shining character as in that 

 order. 



In all Squirrels, the under part of the tail presents an almost naked narrow mid-tract, 

 from which the long hairs diverge : the Aye-aye resembles the Malmags in their growth 

 uniformly from the whole circumference of the tail. 



In proceeding to a comparison of the locomotive members of the Aye-aye, we obtain 

 an instructive test of the relative value of digital and dental characters in determining 

 the ordinal affinities of a Mammal. Had the limbs only of the Aye-aye first reached 

 the zoologist, it can scarcely be doubted but that the same conclusion of their being 

 those of a Lemur would have been arrived at, as was expressed by the name applied to 

 the Aye-aye by the naturalists (Schreber, Illiger) who guided themselves by the 



