Geology and Natural History. 397 



II. Geology and Natural History. 



1. Note on a Bridger Eocene Carnivore ; by O. C. Marsh.* — 

 A reexamination of the three species of the genus Limnocyon 

 described by me in 1872 (this Journal, vol. iv, pp. 122, 203, and 

 204), leads to the conclusion that the type is in all probability to 

 be referred to the genus Sinopa, Leidy, from the same horizon. 

 While this statement applies to Limnocyon verus, the species 

 first described, yet a second species of the genus, Limnocyon 

 ripariics, described by me in the paper cited, is undoubtedly dis- 

 tinct, and cannot be placed in any known genus of Eocene 

 Carnivora. Since the type species of the genus, however, is thus 

 shown to belong to Sinopa, the generic name Limnocyon must be 

 abandoned and another substituted. I therefore propose the 

 name Telmatocyon, basing the genus on the remains referred to 

 Limnocyon riparius. . 



The generic characters may be stated as follows : 

 Dentition : I T , C r , Pm T , M ¥ ; two lower molars subequal in 

 size and tuberculo-sectorial in pattern; internal cusps of these 

 teeth considerably reduced, as in Sinopa ; jaw very straight on 

 inferior border, not unusually deep, but relatively thick and heavy, 

 symphyseal portion abrupt and robust ; first superior molar with 

 external cusps well separated, and not closely approximated as in 

 Sinopa. 



This genus thus differs from the contemporary Viverravus, in 

 the unreduced condition of the second lower molar as well as in 

 the character of the jaw ; from Vulpavas, in having two instead 

 of three lower molars ; and from Sinopa as already indicated. 



2. The Age of the Franklin White Limestone of Sussex County, 

 New Jersey ; by John Eliot Wolff and Alfred Hulse Brooks, 

 Eighteenth Annual Report of the IT. S. Geological Survey, 1896- 

 97, Part II, pp. 425-457, 1898.— Messrs. Wolff and Brooks have 

 made a careful study of the white limestone of Sussex County, 

 which, with the blue limestone of the same region, has been the 

 subject of many papers of those attempting to determine the age 

 of the limestones. Mr. Nason, in 1890, gave at the time what 

 seemed to be conclusive evidence of the Cambrian age of the 

 white limestone, attributing its crystalline condition to the intru- 

 sion of igneous rocks, and also maintained that the white and 

 blue limestones passed one into the other. The present writers 

 have reached the conclusion that the white limestones are pre-Cam- 

 brian in age, and that the quartzite and blue limestone are Cam- 

 brian. Their conclusion regarding the relationship of these is as 

 follows : " That the white limestone was deformed and meta- 

 morphosed to its present condition and partly eroded before the 

 basal member of the Cambrian series was laid down ; that the 



*This note was prepared by Dr. J. L. Wortman, who first called Professor 

 Marsh's attention to the points of synonymy as here given. The matter was left 

 incomplete at the time of Professor Marsh's death. — Ed. 



