552 ORIGIN OF LEMURS 



One of these early forms is referred to the genus Mixodectes, a 

 genus which has been placed, though with a query, in the order 

 Kodentia. It appears, however, to be a Lemuroid, and is of 

 American range. The incisor teeth have been held to argue 

 that it lies on the direct track of Chiromys ; but other features, 

 more especially the form of the astragalus, have been used to 

 argue the justice of the inclusion of thrs type within the order 

 Rodentia. Allied, as it is supposed, to this form is Indrodon, 

 also of the lowest Eocene deposits of the United States. Indrodon 

 mcdaris is known from fragments of nearly all parts of the 

 skeleton. They indicate the existence of a creature of about one- 

 half the size of Lemur varius. It had slender limbs and a 

 long and powerful tail. The humerus, as in so many archaic 

 beasts, has an entepicondylar foramen. The femur has three 

 trochanters, and the fibula articulates with the astragalus. It is 

 not always easy to distinguish these primitive mammals from 

 each other, so that the minutest of characters have to be called 

 in to our assistance. One of the contemporaneous groups with 

 which these early Lemurs might be confused is that of the 

 Condylarthra ; it is important, therefore, to note that in Indrodon 

 the calcaneo-cuboidal articulation is nearly flat, and not bent as 

 it is in the former group. The teeth are of the tritubercular 

 pattern. The incisors are not known, but the molars and pre- 

 molars are each three. To the same family, which has been 

 termed Anaptomorphidae, is referred the genus Anaptomorphus, 

 which has been specially compared to Tarsius. This small 

 animal has a Lemurine face with huge orbits. It has a pre- 

 molar less than Indrodon. It has been ascertained that A. 

 homunculus had an external lachrymal foramen. 1 



Another family, that of the Chriacidae, appear to hover on 

 the border line of Lemurs and Creodorits, having been referred to 

 both by various palaeontologists. Professor Scott suggests their 

 Lemurine or at least Primate relationships, while Cope urged 

 their Creodont affinities. A difficulty raised by Scott was, that 

 m Chriacus the premolars of the lower jaw were spaced. But it 

 appears that this is not fatal to their inclusion in the Primates, 

 since Tomithtrium, an "undoubted Primate," shows the same 

 feature. If G'kriatus is a Lemur it is an earlier type than those 



1 See Schlosser, BeitragePal. Osterr. Hung. 1888 ; also Osborn and Earle, Bull. 

 Arner. Mus. Xat. ffist. vii. 1895, ]>. 16. 



