SEMNOPITHECUS MAURUS. 



teeth are long, acuminate, triangular, slightly tending outward and twisted, with a 

 deep longitudinal groove along the surface, that faces the opposite tooth, and an 

 obsolete groove along the inner surface. Of the grinders, the second bicuspidate 

 is somewhat larger than the first; they are both divided by a deep longitudinal 

 groove, and the exterior point is considerably more prominent than the interior. 

 The structure of the first and second of the quadricuspidate is perfectly uniform ; 

 the crown is divided by a longitudinal and by a transverse groove, which constitute 

 four elevated acute points: the third quadricuspidate differs from the others, in 

 being terminated posteriorly by a very obscure ridge. Of the front teeth, in the 

 lower jaw, the intermediate teeth are both longer and broader than the exterior 

 teeth ; the latter have a slight curvature, and an obsolete heel at the base, which 

 affords them a peculiar character. The canine teeth are shorter than the corre- 

 sponding teeth in the upper jaw, nearly vertically disposed, slightly arched, rounded 

 anteriorly, and obsoletely grooved posteriorly. The first grinder, which follows, has 

 a structure essentially different from the first bicuspidate in man ; it is pyramidal, 

 and terminates in a single point, which is very acute, and projects far beyond the 

 regular series of grinders. The angular surfaces are unequal. The largest, which 

 affords the most distinguishing character to this tooth, is situated anteriorly and 

 exteriorly; it constitutes a very extensive oblique plane, which, in mastication, 

 is applied to the broad interior surface of the canine tooth in the upper jaw : a 

 smaller plane meets this from the opposite interior side of the tooth, and constitutes 

 a sharp ridge, rising to the point of the tooth, which is somewhat obliquely trun- 

 cated by a rough serrated edge : posteriorly, the tooth is defined by a smaller exterior 

 and interior surface. The next tooth, which answers to the second bicuspidate, 

 has generally the same form as the corresponding tooth in the upper jaw, but a small 

 additional ridge exists posteriorly near the base of the crown. The first and second 

 quadricuspidates agree with the corresponding teeth in the upper jaw, presenting 

 individually four regular acute points ; but the third has an additional fifth point, at 

 its posterior extremity, occupying nearly two-thirds of the breadth of the tooth, 

 but, being above, less acute than the other points. It may be observed, that the 

 grinders in the lower jaw are, upon the whole, narrower than these teeth in the 

 upper jaw. 



I refer to the Plate of Illustrations annexed to this Number for an accurate 

 view of the teeth as above described. In letters A. B. C. D. E. F. <§ G. all the 

 details are carefuUy represented, and the separate parts are referred to in the Expla- 

 nation of the Plate. My principal object has been to exhibit accurately the first 

 grinder in the lower jaw, so as clearly to illustrate the description : it is represented 

 therefore both in connexion with the general series, and separated from it. The 



