Lemiv's of the Hapalemur Group. 



345 



So far as I am aware, tlie only other name which can come 

 peuericallj into the little group of lemuroid species exemplified 

 by grisens of I. Geoff roy is Prohmur, which was used by 

 Gray first in a subgeneric, then in a generic, sense for the 

 species he described as simu.i. It appears to me that full 

 generic rank should be assigned to this form. The characters 

 upon which this opinion is based have been either fioured or 

 described l)y ])revious authors — notably by Gray, Beddard, 

 Milne-Edwards, Grandidier, and Elliot, — who, however, did 

 not attach so much importance as 1 do to the differences 

 between griseus and simus where they were appreciated*. 

 These differences appear to me to be of considerably greater 

 systematic value than those which distinguish such genera 

 as Chirofjcdexis and Microcehus, for instance. 



To our knowledge of Prohiuur simus I have nothing to 

 add. In the subjoined comparative diagnoses of Hapalemur 

 and ProJemur I have merely made use of characters in Pro~ 

 lemur which have been stated by otiiers or are apparent in 

 their published iigures. 



Hcipaletmir, Geoff r. 



Type, grisens, I. Geoffr. 



Gland on forearm present in 

 both sexes. 



Nasals long-, extending- back be- 

 yond lacrjnial ibraaiiua. 



Interorbital constriction not ex- 

 ceeding- half the -width of the post- 

 orbital constriction. 



Mesopter\ g-oid fossa much longer 

 than its greatest width in front. 



Widtli across paroccipital pro- 

 cesses at most a little greater than 

 length of nasals. 



Midiir oritice large, set back be- 

 hind middle of orbit. 



Symphysis of mandible strongly 

 curved, chin rounded. 



lianius of mandible slightly 

 everted behind dental line. 



Upper pm^ much lo-wer than 

 canine, a little higher than pm- ; 

 jjvr and pm^ unlike in size and 



Prolenmr, Gray. 



Type, simus, Gray. 



Gland on forearm present ia 

 neither sex. 



Nasals short, not extending back 

 to level of lacrynial foramina. 



Interorbit.al constriction con- 

 siderably more than half the width 

 of the postorbital constriction. 



Mesopterygoid fossa shorter than 

 its greatest width in front. 



Width across paroccipital pro- 

 cesses much greater than length of 

 nasals. 



Malar orifice small, set forwards 

 nearly in line Avith middle of orbit. 



Symphysis of mandible not 

 strongly curved, chin flattish. 



IJamus of mandible strongly 

 everted behind dental line. 



Upper pm^ shghtly lower than 

 canine, much higher than ^jm^ ; 

 p}ii^ and 2)m^ approximately alike 



* Giay's opinion, for example, that the species described by Schlegel 

 as Hapalemur (/risens was the same as his H. simm attests failure in this 

 respect on his jpart ; and Beddard, when he suggested that Mivart had 

 identified siiiws as griseus, must have overlooked that author's description 

 of the teeth. 



Ann. (& Mag. N, Hist. Ser. 8. Vol xix. 23 



