﻿64 SMITHSONIAN MISCELLANEOUS COLLECTIONS [VOL. 47 



all the specimens studied, and in the type, according to the original 

 description, there are but three plates following the anal plate. 



Formation and locality. — Hamilton : Beargrass quarry, Louisville, 

 Ky., and Clark county, Ind. Onondaga: Columbus, O. 



Cat. No.35,141, 36,019 (Rominger collection), and 43.154 (Ulrich 

 collection), U. S. X. M. Also, Xo. 1,220, Massachusetts Institute 

 of Technology. 



MEGISTOCRINUS DEPRESSUS (Hall) 



1862. Hall. 15th Rep. N. Y. State Cab. Nat. Hist., p. 134. 

 1895. Megistocrinus ornatus Miller and Gurley. 111. State Museum of 

 Nat. Hist., Bull. 7, p. 42, pi. 11, figs. 15, 16, 17. 



A comparison of the figures and descriptions of M. depressus 

 (Hall) and M. ornatus M. and G. shows but slight differences 

 between the two forms. The tegmen of the former is said to be 

 " depressed " while that of the latter is " highly convex." In a series 

 of specimens otherwise indistinguishable the height of the tegmen 

 varies considerably, and the depressed tegmen may be due to 

 mechanical pressure. 



The base of M. depressus is said to be " flattened but not ex- 

 cavated," but specimens possessing all the other characteristics of 

 the species have the base " a little concave below " as in M. ornatus. 

 This certainly cannot be relied upon as a distinctive characteristic. 



The only other difference recorded is in the absence of central 

 nodes on the plates of M. ornatus, but as these nodes on M. depressus 

 are extremely minute and easily worn away their absence is of little 

 value as a distinguishing feature. 



None of the differences noted appears sufficient for the separation 

 nf the species, and M. ornatus M. and G. becomes a synonym for 

 .11. depressus (Hall). 



Formation and locality. — Hamilton: Louisville and Lebanon, Ky., 

 and Charlestown, Ind. Onondaga: Columbus, < >. Probably also 

 in the Hamilton at Bartlett's Mills, near Thedford, Ontario. 



Cat. No. 36,018 (Rominger collection), 42,430 and 4 2 433 (Ulrich 

 collect inn ), and 26,467 U. S. X. M. Also 1,224 Massachusetts Insti- 

 tute of Technology. 



MEGISTOCRINUS FARNSWORTHI White 

 [876. White, Proc. Acad. Nat. Sci. Phila., xxvin, p. 29. 

 Tlic specimens of this species are reported by their collector as 

 rare fossils at the type locality. 



Formation and locality. — Middle Devonic : Solon, Iowa. 

 ( *at. Xo. 35.142. 



