tuic Sjiecics of Aoius. 201 



not cxteiuliii^ back beyotul llie forclicud. Mo. liuti stripe very 

 ii;uTo\v at nntcrior ciul, s|)re}ulin^ out into a diarnond-sliapti I 

 mark on tlio foivlifuil. None of tlie stripes uniteil at tlieir 

 posterior tcrtniiiatioii.-^. Lij^lit marks al)ovo eyes very broad 

 iind white. Under surface of body yel|()\vi.sli (mar.s-yellow 

 no. 1, * llepcrtoiro de C'onleurs '). Underside of liml>s similar 

 in col(Mir to belly, becoming greyish towards tlie extremities, 

 especially the liind limbs. Hasal portion of tail reildish (fan- 

 eolour no. 1, 'Repertoire de C!ouleurs'j, becomin;^ black 

 towards the middle, from which i)oint to the tip the tail is 

 completely black. 



Skull much narrower across (he orbits than that of .-1. bo- 

 Ih'iettsis. 



Dimensions of the type (measured in skin) : — 

 Head and body 380"mm. ; tail 390; hind foot SG. 

 ISkull: greatest length 65; basilar length 40 ; zygomatic 

 breadth 3(J ; greatest breadth across orbital region 41"4 ; 

 eondylo-basilar length 45*4 ; )>aiatilar lengtli 17 ; lenL,'th of 

 upper tooth-row, fium front of tirst premolar to back of last 

 molar, 15. 



I/ab. Pozuzo, Peru. Altitude 2400 feet. 

 T//pe. Sul.adult female. B.M. no. 8. 6. 17. 6. Collected 

 by L. i^'j:v:; in Much 1U05. A second specimen trom the 

 same locality is quite similar to the type. 



This species is sharply marked off from .1. hoUvieasis by 

 its much narrower skull, and from A. nigriceps by the black 

 head-stripes being wholly contined to the forehead, not 

 spreading on to the crown of the head. 



Aotus gulans, sp. n. 



Allied to Aotua trivirgatus, Ilumb., but having tlie black 

 head-stripes continued back on to the neck in the form of a 

 well-marked V. 



Size and general characteristics as In ^1. trivirgatus. Hair 

 of medium length, measuring about 23 mm. long on back. 

 General colour of back buiFy brown (snutl-brown no. 1, 

 ' lie[)ertoire de Couleurs'), speckled with black and silvery 

 white, paling to greyish buff on the tlanks and upper sides of 

 limbs. Backs of hands and feet dark brownish black, 

 sprinkled with buff. Stripes on head blackish brown, broad 

 ami well-dctiued. Lateral stripes continued back on to tha 

 neck, where they meet one another, forming a V-shaped mark 

 on the crown and neck. Median stripe ratlier broad on the 

 forehead, becoming narrower on the crown, where it extends 

 back to meet the two lateral stripes at their common point of 



