258 On the Genera of HapaliJfB. 



As has been stated, Gray split the genus Hapale into a 

 number of genera, using the liair-growths or the ears and tlie 

 adjoining parts of" tlie head *. These characters are useful 

 for grouping the species ; but if generic value be assigned to 

 them, a much higher value must consistently be granted to 

 the characters by which the genera admitted in this paper 

 are distinguished. 



Table of the Genera. 



a. Hands -witli long narrow palm and long digits ; digits 



3 and 4 closely tied together by a narrow web 

 reaching nearly to distal end of first phalanx ; a 

 similar but shallower and wider web betweeji digit3 

 2 and 3 ; [ears as under h' ; incisors as under «^] . . Leontocebus, 



b. Hands with comparatively broad short palm and 



short digits separated approximately down to plantar 

 pad. 

 «'. Laminate margin of pinna complete above, but 

 tapering away below and vanishing compara- 

 tively high up on the posterior surface of the 

 basal cartilaginous capsule ; [jncisors as under d^\. CEdijwmidas. 

 b'. Laminate margin of pinna widely continuous 

 ro md tbe cartilaginous capsule, and terminating 

 below the antitragus close to the head. 

 a^. Lower incisors normal, shorter and narrower 

 than the canines, and separated from them ; 

 chin broad, receding to a comparatively' slight 



extent Mystax, 



b-. Lower incisors long, forming a subspatulate 

 series with the canines, which at most exceed 

 by a little the outer incisor in height and thick- 

 ness ; chin somewhat compressed and generally 

 strongly receding Hapale, 



Note. — Daring the passage of this paper through the press, 

 the opportunity has arisen of examining a specimen of Mystax 

 mystax preserved in alcohol. Confirming what has already 

 been stated of this species, I may add that the ears resemble 

 those of Mystax midas and that the hands and feet are of the 

 type seen in Jrlajxde and (Edipomidas. It is interesting to 

 note, however, that on the right hand, but not on the left, 

 theie is a deeper web between the third and fourth digits 

 than I have as yet observed in the case of those genera. 

 The web, nevertheless, is wider and shallower than in Leonto- 

 cebus., although its presence adumbrates the syndactylism 

 described in that form. 



* Bj' analogy the two species of Cercocebus — albigena and aterriinvs, 

 the latter with obsolete, the former with long tufted whiskers — should 

 be generically separated. Elliot, I may add, placed these two species in 

 a subgenus Lophocebits ; but one of the characters justifying this course 

 was derived from an immature deformed (probably menagerie) skull. 



