F. B. Meek on new Silurian Crinoids and Shells. 299 
specimens of this shell I have seen. I am also indebted to him for 
some broken valves showing the hinge. For the use of a good 
specimen showing the hinge of the left valve I am likewise under 
obligations to C. B. Dyer, Esq., of Cincinnati. 
Locality and position—Forty miles west of Cincinnati, Ohio, 
above the middle of the Cincinnati group, of the Lower Silurian. 
ANODONTOPSIs ? UNIONOIDES Meek. 
nearer the anterior side, and its dorsal margin is not declining on 
the posterior side of the beaks as in the last. It likewise differs 
in having its posterior umbonal slopes more convex on a line from 
the beaks to the posterior basal margin. : : 
ength, 1-73 inches; height, !*11 inches; convexity, 0°63 inch. 
Locality and position, same as last. The only specimen I have 
seen was kindly loaned to me for description and illustration, by 
Mr. §. A. Miller, of Cincinnati. 
Remarks on the genus Lichenocrinus; by F. B. Mex. 
Perhaps of all the remarkable types of that protean order of 
animals known as the Crinoidea, there are few more curious and 
interesting forms (if really the 6o0dy of a Crinoid) than that for 
which Prof. Hall baste | the name Lichenocrinus. Having re- 
on 
Some interest to paleontologists, especially as this fossil is little 
known, and the specimens now obtaine afford the means of giv- 
ing a more extended description of its characters than that al- 
ready published. ees 
rof. Hall’s generic description of this crinoid reads as follows: 
Bodies parasitic on shells and other foreign substa ces. Form 
i 
rising from the centre. Disk composed of an indefinite number o: 
polygonal plates, and apparently having no distinct mee of _ 
Tangement. Proboscis perforate, and in the known species, age 
of five ranges of short plates alternating and interlocking at the 
Margins,” 
a From the specimens now known 
eseripti ‘this fossil ma iven: ; 
i Bal or iepaaeed slaneeonves bodies, growing firmly a 
tached to shells, corals, trilobites and other marine objects, an 
, the following more extended 
