52 Mil. R. I. POCOCK ON THE EXTERNAL 



Rodentia. These cranial features distinguish Chiromys from all 

 Lemurs ; and when taken in conjunction with the teeth, with the 

 peculiarities of the hands and feet, and of the sublingua, they out- 

 weigh, in my opinion, the known differences between the true 

 Mascarene Lemurs (Lemurida? and Indrisidse) and the Asiatic 

 and African Galagos, Pottos, and Lorises. 



3. With regard to the Galagos, Pottos, and Lorises, I am oidy 

 acquainted with one invariable cranial chai"acter distinguishing 

 them from the Lemuridje and Indrisidae. This was pointed out 

 by Forsyth Major and has been briefly expressed by Mr, Gregory* 

 as follows : — In the Asiatic forms the ectotympanic is enlarged 

 and external to the bulla of which it forms the outer wall. In 

 the Mascarene forms the ectotympanic is inclosed within the- 

 bulla, forming a ring or horseshoe. To this difference may be 

 added the one pointed out above in connection with the clitoris, 

 Avhich in the Asiatic genera is traversed by the urethra, whereas 

 in the Mascarene forms the urethra opens above the tip of the 

 clitoris. 



In view of these facts, I should divide the Lemuroidea into 

 two series, for which Mr. Gregory's names Lemuriformes for the 

 Lemuridie and Indrisidse, and Lorisiformes for the Loiisidse (or 

 Nycticebid?e) and the Galagidse may be adopted. Similarly 

 for the subdivision of the Lemuridfe I follow Mr. Gregory in 

 relegating the genera to two subfamilies, the Lemurinfe and 

 Chirogaleinse ; but I cannot agree with him that Hapalemiir 

 belongs to the ChivogaleinBe. That genus appears to me to be 

 essentially a Lemurine, its inclusion in the Chirogaleinee spoiling 

 the definition of the subfamily. 



4. As a matter of minor interest it is quite clear that the- 

 genus Lemur as generally admitted and as recognised in this 

 paper is susceptible of division into two or three genera. L. ccdta, 

 for instance, differs from the other species in having the glands 

 on the fore-limb and the naked heel and scrotum, and also 

 in the structure of the vulva. L. variegatus is also peculiar in 

 the structure of the vulva. Furthermore, -the Galagos of the 

 G. senec/alensis-ty-pe may be distinguished by the structure of the 

 penis from that of the c)-assicai{,dcUus-tjY)e. Generic names 

 appear to be available for these subdivisions of Lemur and 

 Galago ; but I do not propose to enter into that question now. 



My views above set forth differ in so many particulars from 

 those of Mr. Gregory that it may be interesting to tabulate our 

 classifications side by side, omitting those he adopts based upon 

 extinct genera, which, so far as I am aware, do not materially 

 affect the arrangement of recent forms. 



* Bull. Geol. Soc. Amev. 26, pp. 432-436, 1915. See also Bull. Aniev. Mas. Nat. 

 Hi-st. 35, pp. 266-267, 1916. 



