346 lAchenocrinus tuber culxdus. 



associated with Glyptocrinus O'NeaUi and Dendroerinus Casei. It has 

 not been found elsewhere so far as known. 



The specific name is given in honor of Dr. L. B. Welch, of Wilming- 

 ton, Ohio, who first discovered the species and called attention to it. 

 Moreover, he has been a collector of fossils and a student of paleontolo- 

 gy for many years, and has a splendid cabinet of rare fossils belonging 

 to this locality. 



Licliejwcrinus tiiherculatus — (S. A. Miller). 



Fig. 38. LicJienocrinus tuherculatus. Enlarged nearly two diameters. 



Body discoidal, circular in outline ; lower surface, or surface of 

 attachment, flat, or conforming to the surface to which it is attached ; 

 upper surface strongly convex or subhemispheric, with a deep circular 

 depression in the central part, around the column ; upper surface of 

 body composed of numerous, irregularly arranged, thin, pentagonal or 

 hexagonal plates, nearly uniform in size, smooth on the under side and 

 highly convex or tuberculated on the outer surface. Excluding the 

 plates immediately surrounding the column, within the central depres- 

 sion, which are much smaller than the others, the remainder will num- 

 ber about one hundred. Interior filled with upright lamelliform plates, 

 radiating from a central point, on which the exterior plates appear to 

 repose. Column i>entagonal, length unknown. 



Diameter of a medium-sized specimen xg^th inch, convexity yV^h inch ; 

 but Mrs. M. P. Haines, of Richmond, Indiana, to whom I am indebted 

 for the specimen engraved, informs me that she has recently found 

 specimens varying from yVtli to -^^^^ of an inch in diameter. 



It is distinguished from L. crater if ormis, which species it most 

 resembles, by its tuberculated plates. It differs, too, in its greater 

 convexity, more abrupt central depression, and greater uniformity in 

 the size of its plates. 



It is found in the vicinity of Richmond, Indiana, in the upper part 

 of the Cincinnati Group. Small specimens, very closely resembling 

 this species in general outline, are found near Clarksville, in Clinton 

 county, Ohio, but differing, in the specimens examined, in this impor- 

 tant regard, that the plates appear to be smooth instead of tubercu- 

 lated. 



