1893.] ^1* [Cope. 



roads, it seems hardly too mucli to hope that the details of the New 

 Jersey field with its extremely useful topographical map could be very 

 rapidly determined. Without the previous Peunsylvania work, the same 

 result would require much labor and time ; and even with the Pennsyl- 

 vania results at hand, the lack of a good topographical map would occa- 

 sion great delay and difficulty in working out the details. Such, for ex- 

 ample, would be the case in the portion of the Pennsylvania Mesozoic 

 field southwestward from the one already mapped. This matter, among 

 many others, gives New Jersey good reason to rejoice in its topographical 

 map as a means of saving great outlays ; while Pennsylvania cannot but 

 find frequent cause to regret its own penny-wise and pound-foolish 

 economy in neglecting so long to make a thorough topographical survey 

 of its whole territory. That neglect is all the more surprising in a State 

 that might well be called the home of American topography as an aid to 

 geology. 



NOTE.— Through a misunderstanding of instructions the lithographer has in the cross- 

 section extended the trap rubbisli all along tlie trap bed, instead of confining it to the 

 surface of tlie ground. 



On the genus Tomiopsis. 



By E. D. Cope. 



{Read before the American Philosophical Society, November 3, 1S93.) 



Tomiopsis gen. nov. Tooth consisting of a much flattened cylinder ot 

 hard dentine, which is enclosed in cementum. The latter forms a layer 

 of medium thickness on the external side, and a very thick layer on the 

 Internal side, which does not extend below the middle of the length. 

 Crown compressed, tapering gradually to the root, the external face sepa- 

 rated fiom the convex interior face by an angle. Pulp-cavity large, 

 extending to near the cutting face, but occupied near the middle (? nor- 

 malljO by a mass of dentine, which substance also forms the centre of the 

 cutting face, which is thus concave on wear. 



The general characters of this tooth are those of mammal of the order 

 Briita (Edentata). It resembles no known form of the order, but might be 

 said to be intermediate between those of an armadillo and a sloth. It, 

 however, differs from both and from membersof the order generally in the 

 gradual anteroposterior contraction of the crown to the root (which is 

 broken off). This circumstance, together with the hollowness of the 

 crown, shows that it is not adapted for continuous service during the life 

 of the animal, but is probablj' a member of a dentition consisting of more 

 than one series. In this respect it resembles the incisor tooth of some 



