48 PROCEEDINGS OF THE XATIOXAL MUSEUM. vol. 37. 



become consolidated, and which was lost when the specimen became 

 interred. The point in the lower border from which the two con- 

 cavities def)art is directly opposite the space between the second and 

 third teeth. In E. crenulatus it is opposite the apex of the second 

 tooth. 



The following- are the dimensions of the teeth of this specimen: 

 Tooth, 1 ; length of base, 22 mm. ; thickness, 8 mm. : tooth, 2 ; length 

 of base, 24 mm. ; height, 10 mm. ; thickness, 8 mm. : tooth, 3 ; length of 

 base, 25 mm. ; height, 19 mm. ; thickness, 8 mm. : tooth, 4 ; length 

 of base, 26 mm. ; height, 19 mm. ; thickness, 8 mm. : tooth, 5 ; length of 

 base, 27 mm. ; height, 19 mm. ; thickness, 8 mm. 



The apical angle of the teeth is 80°. That of E. minor is 35° or 

 40° ; that of E. crenulatus., as already mentioned, is 90°. The an- 

 terior edge of the teeth is concave; the posterior is nearl}^ straight. 

 The teeth are furnished with denticles, but the edges of these are 

 perfectly smooth. The surfaces of the teeth are enameled. From 

 the base of each tooth a number of sharply defined and frequently 

 anastomosing ridges rise to the apex. The forwardly directed proc- 

 ess of each tooth is brought up close to the base of the next tooth in 

 front. 



In front of the first tooth there is, as in E. crenulatus^ a groove 

 that was originally occupied by a series of earlier- formed teeth. The 

 higher and more pointed teeth, with concave anterior cutting edge 

 and smooth denticles, distinguish this species from E. crejiulatus, 

 which it most resembles. 



EDESTUS MINUSCULUS, new species. 



Edestus ef. minor IvARriNSKv, Verliamll. rnss.-kais. min. Gesellsch. St. 

 Petersb., 2d ser., vol. 26, 1898, p. 379, pi. 4, figs. 12, 13. 



As cited above, Karpinsky identified provisionally as E. minor and 

 described with illustrations a single tooth of an Edestus which had 

 been found in the lowermost Permian, the Artinskian stage, near Mos- 

 cow, Russia. A comparison of Karpinsky's description and figures 

 with the numerous good figures that have been published of E. minor 

 Newberry has convinced the writer that the tooth in question belonged 

 to a species quite distinct from E. minor. 



The tooth in Karpinskj^'s possession was a small one, the height 

 from the base of the enamel to the apex, measured along the axis of 

 the tooth, being onh' 14 mm., plus 1 mm. or 1.5 mm. that had been 

 broken from the apex. It was therefore only about half as large as 

 the specimen figured by Newberry ** and by Eastman .^ We must 



« Geol. Surv. 111., vol. 4, pi. 1, fig. 2. "E. vorax." 

 * Mark Anniversary Volume, pi. 21, figs. 2, 3. 



L 



