358 Systematic Paleontology 



is compressed to form a sharp anterior-lateral cutting edge, the base being 

 excavated in front. The posterior-internal surface is full and rounded 

 and prominently longitudinally striate. 



This species was described by Leidy from a fragmentary dentary bone 

 collected from the- Fox Hills Cretaceous of Dakota, and he made it the type 

 of a new genus, Phasganodus. Cope, in 1875, pointed out its identity with 

 the genus Encli odus, and recently Stewart has referred material from the 

 Niobrara formation of Kansas to this same species. The incomplete 

 dentary figured was found in the Monmouth formation of Maryland. It 

 is undoubtedly identical with the material described by Stewart from 

 Kansas, but there is some question of the identity of these forms with 

 Leidy's type. The species has not been recorded from the New Jersey 

 Cretaceous, although some of the detached teeth made the basis of specific 

 names might represent it. 



Occurrence. — Monmouth Formation. Brooks estate near Seat 

 Pleasant, Prince George's County. 



Collection. — Maryland Geological Survey. 



Order ACTINOPTERYGII 



Suborder HAPLOMI 



Family LUCI1DAE (ELOP1DAE) 



Genus 1SCHYRHIZA Leidy 



[Proc. Acad. Nat. Sci., Phila., vol. viii, 1856, p. 221] 



Ischyehiza miea Leidy 

 Plate IX, Figs. 6-8 



Ischyrhiza mira Leidy, 1856, Proc. Acad. Nat. Sci., Phila., vol. vili, p. 221. 



Ischyrhiza antiqua Leidy, 1856, Ibidem., p. 256. 



Ischyrhiza antiqua Emmons, 1858, Rept. N. C. Geol. Survey, Eastern Coun- 

 ties, p. 225, tf. 47, 48. 



Ischyrhiza mira Leidy, 1860, in Tuomey and Holmes, Post-Pleiocene Fossils 

 of South Carolina, p. 120, pi. xxv, figs. 3-9. 



Ischyrhiza mira Cope, 1875, U. S. Geol. Survey Terr., vol. ii, p. 280. 



Ischyrhiza mira Hay, 1902, Bull. U. S. Geol. Survey, No. 179, p. 398. 



Ischyrhiza mira Fowler. 1911, Bull. 4, Geol. Survey of New Jersey, p. 167, 

 fig. 103. 



