MICROCH^RUS. 115 



Wasatch strata of Wyoming, and the Puerco beds in New 

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

 Lemurs, namely l^, ^Uo^ -^f^j ^h I'"' 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 i^Chirogale). 

 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-j, M J. 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. MiCROCHiERUS 

 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 



