MARYLAND GEOLOGICAL SUEVEY 93 



pany with three other Actinopterygians, as follows : Phyllodus curvidens 

 Marsh, Crommyodus irregularis Cope, and Phasganadus gentryi Cope. 

 The Eocene and Miocene of Virginia combined yield scarcely a half- 

 dozen species of bony fishes, and this group is represented with equal 

 meagreness in North and South Carolina. In all these states, how- 

 ever, and especially in the Eocene of Alabama and Mississippi, Teleo- 

 stome otolites (Plate XXXII, Figs. 17, 18, 19) occur in considerable 

 abundance and variety; and it happens that these insignificant appear- 

 ing objects are the only record that remains of a once flourishing fish- 

 fauna, which can be but inadequately reconstructed in imagination. 

 Many of the Miocene otolites occurring in this state are indistinguish- 

 able from those figured unaer a variety of titles from the Eocene of 

 Alabama and Mississippi by Koken.^ 



The problematical genus Iscliyrhiza, to which attention was directed 

 in the Eocene volume, may be dismissed with the statement that Cope's ^ 

 reiterated assertion that " this or an allied genus is quite abundant in 

 the Miocene of Maryland " remains up to the present time entirely 

 uncorroborated. It is evident that this remark of Cope's applies only 

 to the fused caudal fans, since he states immediately afterwards that 

 " the teeth of the species have not been obtained." As for the tooth 

 described by Leidy from North Carolina under the name of I. antiqua, 

 Cope suggests it may have been a derived fossil of Cretaceous age, 

 instead of Miocene. There is accordingly some reason for doubt 

 whether either the teeth or the fans really continue into the Miocene, 

 although they are unquestionably present in the Eocene. As already 

 set forth in the preceding volume on the Eocene, the theoretical asso- 

 ciation of these teeth and fans under a single genus appears decidedly 

 improper, and unwarranted by any facts. The name Ischyrhiza should 

 be restricted to include only the teeth such as were first described by 

 Leidy; and as for the fans, since they in all likelihood belonged to 

 some of the Sword-fish tribe, they may be provisionally assigned to the 

 genus XipTiias. 



1 E. Koken, Neue Untersuchungen an tertiaren Fisch-Otolithen (Zeit. d. deutsch. 

 geol. Gesell., voL xliii, 1891, p. 77). 



2E. D. Cope, Vert. Cret. Formation West (Kept. U. S. Geol. Survey Territ., vol. ii, 



1875, p. 280). 



