VERTEBRATES. 83 



be a strong resemblance to the large tooth found at Oreton, in 

 Shropshire, drawings of which were kindly communicated by Lord 

 Enniskillen, showing a tooth of nearly equal dimensions and differ- 

 ing chiefly from the present form in the less prominent and well 

 defined posterior coronal lobe, and perhaps less massive proportions 

 in the region of the coronal prominence. The latter form we are 

 not aware has been described. The distinctions of the present form, 

 compared with the smaller forms hereinafter described, need not 

 receive further notice in this place. The Belgian Carboniferous 

 tooth described by Dr. L. de Koninck under the name Streblodus 

 tenerrimus, is under medium size, and is further distinguished from 

 the present tooth by its relatively narrower posterior prominence 

 and stronger spiral inrollment. 



Geological position and locality: This unique example was derived 

 from the uppermost bed of the Kinderhook series exposed in the 

 banks of Long Creek, a tributary of Skunk river, Des Moines Co., 

 Iowa. 



VATICINODUS DISCREPANS, St. J. and W. 



PI. Ill, Fig. 2, 3. 



The collections contain three or four examples of maxillary pos- 

 terior teeth, which, although in a fragmentary state of preservation, 

 apparently differ from any of the associated species thus far made 

 known from the Upper Burlington horizon, in which the present 

 form was discovered by Mr. Springer. They are evidently referable 

 to the above genus, and offer the following distinctive features, es- 

 pecially compared with the much more prevalent forms of Stenop- 

 terodus planus, with which they are associated, and for which they 

 are most liable to be mistaken : Attaining a larger size, the teeth 

 are specially distinguished by the much more rapid convergence 

 of the postero-lateral border, and the consequent greater ob- 

 liquity of the coronal prominence, which presents a broad, very 

 slightly convex posterior slope, and abrupt declivity in front, where 

 it is defined by a slight angulation from the plain anterior area. 

 The inner margin is more sharply rounded in the region of the base 

 of the coronal prominence, slightly concave or constricted in front, 

 and thence to the obtute anterior angle it pursues a gently arched 

 or nearly direct course. The coronal surface shows minute, closely 



