192 DR. GIBBES' MONOGRAPH OF THE 



2. G. LATiDENS, Agassiz. Figs. 59, 60, 61, 62. — Is much less massive and thinner 

 than G. aduncus, but is longer in proportion to the height. The anterior edge is less 

 arched than in other species. The cone is short and very pointed on the posterior 

 edge, the angle is very acute in the European species, I think less so in the 

 American. Below the angle the dentelures are well marked, w^hile at the cutting 

 point and on the anterior edge they are very fine. In some specimens they are more 

 distinct near the base on the anterior edge, while in Agassiz's specimens he mentions 

 the reverse, and makes it distinctive of a species. The base of the crown is parallel 

 to the lower edge of the root on the outer face, and differs very slighlly on the inner. 

 I have several specimens from the Eocene of South Carolina, and one from the 

 Miocene of Maryland. For the latter I am indebted to my friend F. Markoe, Jr., of 

 of Washington. 



3. G. MINOR, Agassiz. Figs. 63, 64, 65. — Very similar in form to G. latidens, but 

 not arched, very small, and the cone more acute. It is almost as high as long — the 

 base of the crown extended — the summit very sharp pointed, edged with fine 

 dentelures on both sides. The root is thick and irregular, the enamel more sloped 

 on the inner or elevated face. 



I have specimens from the Eocene of South Carolina, and from the Miocene of 

 Maryland — the latter sent me by J. G. Bruff, Esq., of Washington. 



4. G. EGERTONi, Agassiz. Figs. 66, 67, 68, 69. — This was described by Agassiz 

 as Corax. The cone is acutely pointed, and nearly perpendicular, sloped on both 

 edges, forming almost an angle on the posterior side in some specimens. The edges 

 are more uniformly indented than in other species. The outer surface is elevated 

 above the level of the root and undulated; the inner much more prominent and 

 smooth. The root is very thick and deep, and forms two-thirds of the height of the 

 tooth. The enamel extends lower on the outer than on the inner face. 



My specimens are abundant from the Eocene of South Carolina. I have a few 

 given me by Professor Wyman, from Richmond, Virginia, and others from 

 Calvert CliflFs, Maryland, {Miocene) by F. Markoe, Jr., and from Hollis CHflFs, 

 Virginia, by J. G. Bruff, Esq. 



The large specimen (Fig. 66) is of unusual size. It is from Pocotaligo, South 

 Carolina, presented to me by G. C. Mackay, Esq. 



5. G. PRiSTODONTUs, Agass. Fig. 70. — This species is remarkable for its 

 pyramidal form, and the great size of its crown ; from the posterior edge being but 

 slightly sloped, and the anterior forming a sort of elbow, and not a regular arc ; the 

 point is nevertheless acute and cutting. The whole height including the root about 

 equals the length, which is sometimes three-fourths of an inch. The dentelures are 



