EASTMAN : CAKBONIFEROUS FISHES FKOM THE CENTRAL WEST. 169 



of Blue Springs, Nebraska, and is shown of the natural size in Plate 2, Fig. 

 4. Inspection shows that Cope mistook the worn base of the crown for a trun- 

 cate root, in allusion to which the name Styptobasis was given; and so far as 

 may be judged from the form and ornamentation of the crown, it differs from 

 the foregoing species merely in the fact of being somewhat more robust. The 

 shallow median depression at the base of the crown on its outer face likewise 

 occurs in C. occidentalis. Another Cladodont tooth, scarcely distinct from the 

 latter species, is described by O. P. Hay under the name of C. (jirUji, from thu 

 Coal Measures of Colorado. 



Formation ami Locality. — Permo-Carboniferous; Blue Springs, Nebraska. 



Phoebodus knightianus, sp. nov. 



(Plate 4, Figs. 40, 40 a.) 



Type. — Imperfect tooth ; Museum of Comparative Zoology. 



From the same locality as the preceding, Professor Knight secured some 

 years ago one nearly perfect tooth and the root of a second specimen, which he 

 cited as '^ Diplodus, sp. nov." in his faunal list of the Kansas and Nebraska 

 Permo-Carboniferous. 1 Through the courtesy of their discoverer, these speci- 

 mens have come into the possession of the Museum of Comparative Zoology, 

 and form the basis of the following description. It is stated in a letter from 

 Professor Knight that his attempt to remove some of the adherent matrix 

 from the more perfect tooth resulted in some injury to the latter, and the 

 broken parts were unfortunately not preserved. He had, however, observed 

 that the three principal cones were all of the same height, and that the base 

 was symmetrically developed. Accordingly, in the figures here given of the 

 fractured specimen, its original outline is restored on Professor Knight's 

 authority. 



Teeth of moderate size, the median and two outer cones of equal height, 

 and no intermediate denticles. All three cusps stout and erect, convex on 

 both faces, with sharp lateral carinae, and a few delicate, slightly curved striae 

 extending for a short distance upward from the base. Attached surface of root 

 nearly plane, with a single patl-like prominence directly underneath the median 

 cone ; postero-superior surface with a rounded "button." 



The root agrees in size and general form with that of Diplodus platypternns 

 Cope, except that both the posterior button and antero-inferior prominence are 

 of relatively smaller size. From Phoebodus politus Newb. and other Devonian 

 species the present form is distinguished by the absence of intermediate den- 

 ticles, a character in which it agrees with the Triassic P. brodiei. The type 

 specimen is shown of four times the natural size in Plate 4, Figures 40 and 

 40 a, but in these illustrations the anterior boss on the lower surface of the root 



1 Journ. Geol., Vol. VII., 1899, pp. 866, 372, 374, 491. 



