Shufeldt: Osteology of Lasiopyga and Callithrix. Gl 



described; in fact, the skull of Callithrix somewhat reminds us, 

 especially when viewed laterally, of the skull in some of the Mustelidcc, 

 e. g., Spilogale piitorius, in the posterior elongation of the cranium, 

 and the aspect of the canines. Viewed anteriorly, the facial aspect 

 of the skull in Callithrix is, however, entirely Simian in all of its essen- 

 tial characters, with its large, cavernous, globular orbits, with theii 

 circular, unbroken peripheries, and their inner walls entirely com- 

 pleted in bone excepting the usual foramina. This is the case in 

 both the species of Lasiopyga before me, wherein all the diameters of 

 either orbital cavity, save the antero-posterior, are longer than 

 the diameters measured from the peripheral borders by several milli- 

 meters. The usual foramina in either orbit are the same as they are 

 in man. Confining ourselves for the present to the characters of the 

 face, we note the marked transverse narrowness of the superior nasal 

 region in L. callitrichus, as compared with the much broader and moie 

 rounded area in L. griseoviridis (PI. XII, Figs, i and 2); while the 

 anterior narial aperture is about the same in either species, being only 

 slightly larger in the last-named form. As in most apes in this and 

 related genera, the maxillary poition of the face is prominent and 

 rounded, though not nearly as much so as in some of the higher 

 Simians, as the orangs and chimpanzees. The premaxillaties form 

 a distinctive feature, together forming the facial area, and being 

 carried up to articulate with the nasals above, the sutural traces being 

 more evident in L. griseoviridis. 



In the specimen of L. callitrichus before me, there is neither notch 

 noi foramen for the supraorbital nerve, while in the Green Guenon 

 there is a minute foramen for the exit of that branch on the left side. 

 In both skulls there are present upon either side from four to five 

 foramina for the exit of the infra-orbital nerve. On the other hand in 

 Callithrix the foramen is single. In this genus also the malar foramen 

 is single, which is likewise the case in L. callitrichus; while in L. 

 griseoviridis there are two upon either side. A peculiar charactei in 

 the face of this last-named species is the deep transverse notch between 

 the nasals and the supra-orbital ridge (Plate XIII, Fig. 4). In both 

 skulls the anterior nasal spine is entirely absent; the lachrymal groove 

 is well marked; and the canine eminence most prominent in L. 

 griseoviridis. 



These apes have the vomer moderately well developed, being 

 weakest in L. callitrichus, in the skull of which at hand I find no 



