56 SCOTT. [Vol. V. 



posterior expansion in width which is so characteristic of the 

 llama. Below the suture of the nasals and maxillaries the latter 

 show a long, deep depression. The anterior nares have an alto- 

 gether different shape from that seen in the existing genera ; 

 they are very low, and their lateral edges are not nearly so 

 oblique, but more vertical in position. The lachrymal and jugal 

 are about as much extended upon the face as in Auchenia; but 

 the notch in the latter, which receives the anterior end of the 

 zygomatic process of the squamosal, is not deep as in the modern 

 species. There is no fontanelle between the nasal, frontal, and 

 maxillary, as is so markedly the case in the llama ; and sometimes 

 even in the camel there is a small vacuity present. The face is 

 not abruptly constricted in front of pm. 4, but tapers gradually 

 forward. The nasal chamber is very low, especially in front ; 

 and in consequence the maxillary has no such vertical extension 

 as in the recent species. The palate is also very different in 

 shape, especially in the absence of the deep constriction in front 

 of the molar series and the very much shorter diastema behind 

 pm. 1. The alveolus is continued further back of the last molar, 

 and forms a very small projection into the orbit ; the palatal 

 notches between the alveoli and the palatines are very short, 

 and the posterior nares have a much less vertical extent. The 

 latter are in shape and position very like those of Auchenia, 

 being long, narrow, and pointed anteriorly, extending to the 

 space between m. 2 and 3. The vomer extends lower, and is 

 more conspicuous than in the modern genera. The descending 

 plates of the ali-sphenoids are shorter, somewhat broader, and 

 do not terminate in such distinct hamular processes ; the same 

 statement applies to the pterygoids, of which the free ends are 

 short and inconspicuous. The tympanic bullae are relatively 

 larger and more rounded, and the styloid groove and pit are 

 shallower and more widely open behind. The zygomatic process 

 of the squamosal is shorter, and the glenoid cavity is not sep- 

 arated into two parts. The occiput is rather high and narrow, 

 and there is a strong lambdoid crest, as in the camel. The con- 

 struction of the roof of the cranium agrees best with the latter 

 genus, as is seen in the shortness of the frontal zone, the long 

 sagittal crest, and prominent lambdoid crest ; but owing to the 

 more posterior position of the orbits, the zygomatic arch and 

 temporal fossa are much shorter. A primitive feature is the 



