Lemurs of the Hapalemur Group. 



345 



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

 genericallj into the little group ot lemuroicl species exemplified 

 by griseus of I. Geoffroy is ProJeinur, which was used by 

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

 species he described as simus. It ai)pears to me that full 

 generic rank should be assigned to this tbrm. The characters 

 upon wliicli this opinion is based have been either figured or 

 described by previous authors — notably by Gray, Beddard, 

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

 not attach so much importance as I 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 Chirogalexis and Microcehns, for instance. 



To our knowledge of Prolemur simus I have nothing to 

 add. In the subjoined comparative diagnoses of Hapalemur 

 and Prolemur T have merely made use of characters in Pro- 

 lemur which have been stated by others or are apparent in 

 their published figures. 



Hapalemur^ Geoffr. 



Type, griseus, I. GeofEr. 



Gland on forearm present iu 

 both sexes. 



Nasals long-, extending back be- 

 yond lacrymal foramina. 



Interorbital constriction not ex- 

 ceedinji: half the width of the post- 

 orbital constriction. 



MesopteryoTjid fossa much longer 

 than its greatest width in front. 



Widtli across paroccipital pro- 

 cesses at most a little greater than 

 length of nasals. 



Malar orifice large, set back be- 

 hind middle of orbit. 



Symphysis of mandible strongly 

 curved, chin rounded. 



Ramus of mandible slightly 

 everted behind dental line. 



Upper /?wt"' much lower than 

 canine, a little higher than jmi^ ; 

 jivi^ and pm^ unlike in size and 



Prolemur, Gray. 



Type, simus, Gray. 



Gland on forearm present in 

 neither sex. 



Nasals short, not extending back 

 to level of lacrymal foramina. 



Interorbital constriction con- 

 siderably more than half the width 

 of the postorbital constriction. 



INIesopter^'goid fossa shorter than 

 its <rreatest width iu front. 



Width across parocciijital 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. 



Iiamus of mandible strongly 

 everted behind dental line. 



Upper pm^ slightly lower than 

 canine, much higher than pvi^ ; 

 pni^ and ^;»i^ approximately alike 



* Gray's opinion, for example, that the species described by Schlep:el 

 as Hapalemur griseus was the same as his //. simiiii attests failure in thia 

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

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

 of the teeth. 



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



