1895.] 



55 



[Slade. 



reference in the howlers to the great development of the vocal organs, 

 rather than to any unusual energy of the masticatory muscles. 



In the Lemuroidea, the family of the common lemurs have an arch which 

 in most cases is nearly straight, narrow, long, and distinguished by a 

 malar-squamosal suture, which is almost horizontal in direction, the 

 amount of the overlapping of the jugal by the lengthened process of the 

 squamosal being exceptional, while in some cases the jugal is partially 

 underlapped by a process of the maxillary. 



As regards the Carnivora, the general characteristics presented by the 

 arch and the adjacent regions have already been considered, when taking 

 that of the tiger as a typical illustration of their morphology. The order 

 of the Carnivora is divided into two suborders, the true or fissiped and the 

 pinniped (the latter being organized mainly for an aquatic life). The true 

 Carnivora may be classified under three sections — ^luroidea, Arctoidea 

 and Cynoidea. The arch in the families comprehended under the first of 

 these sections presents no modifications specially different from those 

 oflered by the Felidae, unless we may except the Hysenidae, in which the 

 jugal arch is extremely wide and strong and the horizontal curvature very 

 great. The postorbital of botli frontal and jugal are largely developed, 

 approximating each other, while the sagittal crest is high, giving large 

 attachment to the very powerful muscle of the temporal. The ascending 

 rami of the mandible present the corresponding extent of surface for 

 muscular attachments. In the section Arctoidea, the family Ursidte 

 present an arch which is longer, and of which the horizontal curvature is 

 greater than that of the Felidoe, while the jugal-squamosal suture is more 

 oblique, and the entire bridge much less developed. In the Musteli'dte, 

 the upward vertical curvature is large, but the entire arch is relatively 

 slender. 



In the Cynoidea, the strength and curves of the arch occupy a position 

 midway between those of the other sections, being more developed than 



