MICROCH/ERUS. 



115 



Wasatch strata of Wyoming, and the Puerco beds in New 

 Mexico. Their dental formula is the same as that of existing 

 Lemurs, namely 1^, C^, P|^, M|. In some of the 

 genera there is a tendency to develop, as Cope has pointed 

 out, large cutting teeth in the position of incisors, " thus 

 approaching the Aye- Aye." The posterior pre-molars are 

 more simple than the anterior true molar, a character which 

 indicates some relationship to the Mouse-Lemurs (C/iiroga/e). 

 The mastoidal or posterior portion of the ear-capsules, and 

 the neighbouring squamosal region of the cranium are swollen, 

 as among the Galagos. 



GENUS MICROCH^RUS. 



Microchcerus^ Wood, Lond. Geol. Journ., i., p. 5 (1846). 

 Heterohyus, Gerv., Zool. et Pal. Fr., p. 202, pi. 35, fig. 14. 

 Necrolemur^ Filhol, C. R., ixxxvii., p. 11 12 (1873); id. Ann. 

 Sc. Geol., viii., p. 55, pi. iv., figs. 213-217 (1877). 



This genus is distinguished from all other Lemurs by " the 

 angle of the mandible being produced into a large hook-like 

 flange." (Flower and Lydekker.) The orbits are large, indi- 

 cating a nocturnal animal ; the inter-orbital space is wide, and 

 distinguishes it from Loris. The dental formula is If^, Cy. 

 P-|, Mf . The canine teeth are not prominent ; the anterior 

 lower pre-molar is only slightly developed ; a gap separates the 

 anterior and the median upper pre-molars. 



This genus is represented by five species. Microch/erus 

 ANTIQUUS (Filhol) is of very small size, and has many affinities 

 with Galago, as exhibited in the well-preserved cranium that 

 has been recovered from the Phosphorites of Central France. 

 The two lower molars have only one root. M. erinaceus, 



I 2 



