L. Hussakof — Note on a Palceoniseid Fish. 347 



Akt. XXY. — -Note on a Palwoniscid Fish from a Permian 

 Formation in Soxith Dakota ; by L. Hussakof. 



Through the kindness of President C. C. O'Harra of the 

 South Dakota School of Mines, I have recently had the privi- 

 lege of examining two fishes from a Permian formation in the 

 Black Hills region of South Dakota. No fish remains had 

 previously been found in this formation, so that the find is of 

 interest as promising to add a new locality for Permian fishes 

 to the two at present known in America — those in Illinois, and 

 in Texas-Indian Territory. 



The fishes thus far collected are all imperfect, the two here 

 described being the best ones found. One is the greater por- 

 tion of a fish, the other merely a fragment of the body of a 

 larger individual. 



The formation and locality are described by President 

 O'Harra as follows : 



"The fishes were found in a quarry three miles northwest of 

 Rapid City, South Dakota, in the Minnekahta limestone,* where 

 the rock is being extracted for road metal and miscellaneous struc- 

 tural purposes. The quarry is under control of the Northwestern 

 Quarry Co. My attention was called to the fish by Mr. Albert 

 Halley, one of the interested members, through whom I secured 

 the loan of the specimen from Mr. L. E. Parrish, who owns it. 



"The Minnekahta limestone throughout the Black Hills i*egion 

 is of fairly uniform character and thickness. At this particular 

 point it is approximately fifty feet and is made up of a nearly uni- 

 form greenish gray to purplish limestone which when observed 

 from a distance seems quite massive, but near at hand shows a 

 thinly bedded or flaggy nature. Near the middle of the forma- 

 tion this flaggy condition is more pronounced and generally shows 

 somewhat distinctly because of more rapid weathering. In this 

 particular quarry, the lower beds are inclined to be fairly massive 

 and the stone obtained from them has served to a little extent as 

 a local building material. 



" The fish-bearing layer is in the lower part, approximately 

 thirty-five feet below the top of the formation. There is nothing 

 especially different in the general nature of the slabs containing 

 the fossils and their presence in the quarry cannot be detected 

 except as the surface bearing them is exposed." 



There are three previous records of fossil fishes from South 

 Dakota, which may here be briefly referred to. In 1878,f 



* Generally regarded as Permian: Bailey Willis, Index to the Stratigraphy 

 of North America, Professional Paper 71, U. S. Geol. Survey, 1912, pp. 

 495-496. 



f Cope, E. D., Descriptions of fishes from the Cretaceous and Tertiary 

 Deposits west of the Mississippi Eiver, Bull. 4, U. S. Geol. and Geogr. Surv. 

 Territories, pp. 67-77, 1878. 



