Geol.-Vol. I,] SMITH— COMPARATIVE STRATIGRAPHY. 385 



The septa are ceratitic, with rounded entire saddles and serrated lobes. 

 The external lobe is divided by a shallow siphonal saddle into two short 

 branches; the first lateral is deeper and broader; the second lateral about 

 one-half as large, and the auxiliary lobe consists of a straight series of 

 denticulations, distinctly separated from the third lateral saddle. 



This species is a genuine nodose ceratite, and seems to 

 belong to the narrow group of Ceratites nodosus. It is 

 nearest to C. evolvens Hauer^ but is more evolute, and has 

 fewer ribs and stronger spines. 



The dimensions of the type specimen, figured on plate 

 xliv, are as follows: 



Diameter 67 mm. 



Height of last whorl 29 mm. 



Height of last whorl from the preceding 24 mm. 



Width of last whorl 24 mm. 



Involution 5 mm. 



Width of umbilicus 18 mm. 



Horizon and locality. Upper part of the Middle Trias, 

 Daonella beds, West Humboldt Range, Nevada, on the 

 divide between Troy Canyon and the south fork of Ameri- 

 can Canyon, associated with Anolcites whitneyi, A. hyatti, 

 A. meeki, Protrachyceras aniericanum, Acrochordiceras 

 hyatti, Beyrichites rotelliformis, Etitomoceras laubei, Sage- 

 ceras gabbi, Daotiella diibia, and many other characteristic 

 species. In this bed there are more than twenty species of 

 genuine nodose Ceratites, most of them apparently new 

 species, though many are closely alHed with Indian and 

 Mediterranean forms. 



The specific name is given in honor of Col. A. W. 

 Vogdes, U. S. A., to whom the writer is indebted for valu- 

 able aid in the bibliography of the Trias. 



Subgenus Gymnotoceras Hyatt. 



•i^'JT. Gymnotoceras, Hyatt, in F. B. Meek, U. S. Gaol. Expl. Fortieth 

 Parallel, Vol. IV, p. no. 



Type, Ammonites blakei Gabb, Pal. Calif, 1864, Vol. I, p. 24, pi. iv, figs. 

 14-15; and F. B. Meek, U. S. Geol. Expl. Fortieth Parallel, Vol. IV, p. 113, 

 pi. X, figs. 10, a-b, (not pi. x, fig. c, nor pi. xi, fig. 6). 



1 See Bibliog. II — pi. vi, fig. 4. 



