43S SMITHSONIAN INSTITUTION 



principal locality, is unquestionably the same as the fine series of specimens which I have 

 illustrated. 



Types. Miller and Gurley's original is in the University of Chicago. The others figured 

 herein are in the author's collection. 



Horizon and locality. Lower Carboniferous, Okaw formation, upper part of Kaskas- 

 kia Group ; Pulaski, Grayson and Breckinridge counties, Kentucky ; Huntsville, Alabama ; 

 and Randolph County, Illinois. 



Onychocrinus wrighti n. sp. 

 Plate LXXV, fig. 14 



A large species, represented by a single specimen considerably injured by 

 pressure. 



Rays strong, deeply rounded and rather clumsy in appearance. IBr 4. 

 Rami much longer than primary rays, stout with but little' taper; strongly 

 divergent, the IIBr entirely separating at the axillary and not being joined 

 for any distance above. Ramules about 8; bilateral, given off alternately first 

 at intervals of one or two brachials, but in the upper part of one ray every suc- 

 cessive brachial is axillary, reducing the intervals of the ramules to those of 

 pinnules; the ramules are very stout, almost as large as the rami and much 

 resembling them in appearance; they branch secondarily on every second 

 brachial, or upon successive brachials from 4 or 5 times in the lower ramules to 

 a single equal bifurcation as usual at the distal end of the ramus. Sutures 

 slightly arcuate in the main rays, becoming straighter distally. Interbrachials 

 apparently not over one. Anal structures not preserved. Surface distinctly 

 marked with fine wrinkles. 



Length of ray to apex of axillary, 20 mm. ; of ramus from axillary to ter- 

 minal bifurcation, 50 mm. ; diameter of column at base, 1 1 mm. Base too much 

 distorted for measurement. 



The solitary specimen on which this species is based was found by Mr. James Wright, 

 Jr., of Kirkcaldy, Scotland, among the interesting collections made by him in the Hurlet 

 limestone at Inverteil ; and I have much pleasure in associating it with his name. It is the 

 first typical Onychocrinus thus far found outside of the United States. Its occurrence 

 along with Hydreionocrinus, Cromyocrinus, Zeacrinus of the Z. wortheni type, and Synero- 

 erinus, points unmistakably to the closing epoch of the Lower Carboniferous, and this is 

 confirmed by its structural affinities, which are decidedly with the latest Kaskaskia species, 

 0. pulaskiensis . The general habitus, with the rather clumsy, slightly tapering rays, and the 

 approach to pinnulation by the further diminution of intervals between ramules, produce 

 a form of substantially the same type. The possession of four primibrachs (which dis- 

 tinctly appear in two uninjured rays), and ornamented surface, distinguish the species. 



Type. In the collection of James Wright, Jr., Kirkcaldy, Scotland. 



Horizon and locality. Upper part of Lower Carboniferous, Hurlet limestone, — cor- 

 related with the Kaskaskia of America ; Inverteil, Scotland. 



