NO. 1192. TRENTON FAUNA OF BAFFIN LAND -SCHUCHERT. 155 



CYSTOIDEA. 



Family CRYPTOCRINID^ Zittel. 



POROCRINUS SHAWI, new species. 



(Plate XIT, figs. 1-3.) 



This species is most nearly related to P. smithi Grant,^ as far as the 

 shape of the dorsal cup, elevation of the costse, and form of the plates 

 are concerned. It differs, however, from all American species in that 

 the circular pore-rhomb spaces are larger. This is particularly true of 

 the lowest series, which occupy nearly the entire basal jilates besides 

 portions of two adjoining subradials. The rhombs are also very large 

 in the interradial areas on each side of the arm bases. 



The ambulacral grooves are narrow and short, and within the shallow 

 vestibule terminate abruptly below into the body cavity. The margin 

 bordering the large, central, circular opening is somewhat notched at 

 ea{;h ambulacral groove, giving the impression that there may have 

 been communication between the oral opening and each ambulacral 

 groove. The smaller ventral plates are not preserved in this specimen, 

 which is the only one known. 



Named for Mr. A. V. Shaw, of Boston, Massachusetts, who was one 

 of the Frobisher Bay party of 1897. 



Collector.— A. H. White. Cat. No. 28145, U.S.N.M. 



Family LICHENOCRINID^. 



LICHENOCRINUS AFFINIS Miller. 



Uchenocrinus affinis Miller, Journ. Cinn. Soc. Nat. Hist., V, 1882, p. 229, pi. ix, 

 figs. 7, la. 



But a single specimen of this species has been noted, and this was 

 attached to an Orthoceras. It has the general aspects of L. affinis iu 

 the pentagonal column, form of body, slight convexity, number of plates, 

 and the general irregularity of these, both in form and arrangement. 



The genus Uchenocrinus has not been previously recorded from rocks 

 below the Utica. In the Cincinnatian group specimens are often abun- 

 dant where L. affinis occurs in the upper third or Richmond stage. 



Collector.— J. ''^. Oarpender. Cat. No. 28L46, U.S.N.M. 



1 Ottawa Field Nat. Club, Trans. No. 2, 1881, p. 42, plate, figs. 1-8. 



