260 IOWA GEOLOGICAL SURVEY 



serrations, a pair of imperfectly preserved frontal bones (pi. 

 1, fig. 6, U. S. G. S. Bull. No. 16) found in natural juxtaposi- 

 tion, and two delicately striated plates, one of which, is eyidently 

 the maxilla stripped of its teeth, (ibid, fig. 4), and the other 

 may perhaps be regarded as the operculum (ibid, fig. 5). The 

 type specimen is preserved in the United States National Mu- 

 seum, and bears the catalogue number 30,842. 



Formation and locality. This species is stated by Dr. Clarke 

 to occur abundantly in bituminous layers of the Naples shale 

 (lower black band of the Portage group) in the town of Sparta, 

 Livingston county, New York. A single scale displaying the 

 same ornamentation is also reported by him from the Genesee 

 shales of Glenville, Hemlock Lake, a few feet above the Styliola 

 layer. Similar scales have been noticed by Dr. G. J. Hinde from 

 the Genesee of Erie county in the same State, and others are 

 reported from the corresponding horizon in Kentucky. No ex- 

 amples from the last-named region, however, have come under 

 the present writer's observation, nor is record to be found of 

 their detailed description. On the other hand the fact deserves 

 mention that patches* showing a considerable portion of the 

 squamation of Eurylepis have been obtained from the Waverly 

 black shale at Vanceburgh, Kentucky. Several specimens of 

 this nature are to be seen in the State College collection at 

 Lexington. 



Rhadinichthys sp. 



1907. Rhadinichthys sp. indes-. C. R. Eastman, Mem. N. Y. State Mus. 10, p. 

 172, pi. 4, fig. 11, and pi. 9, fig. 4. 



A single small thick-scaled Palaeoniscid fish, too imperfect 

 for accurate determination, was obtained some years ago by 

 Mr. F. A. Eandall from the Chemung rocks of Warren, Penn- 

 sylvania, and is now preserved in the Museum of Harvard Uni- 

 versity. The specimen is chiefly interesting on account of its 

 excellent display of median and paired fin characters. These, 

 together with the general form of the body and scale characters 

 have suggested a position for it in the vicinity of R. elegantulus 



* Remains of this nature are by no means uncommon, and are perhaps to be 

 explained as voided contents of the intestinal tract of predatory fishes. 



