24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 'jd 



grooves, one for each arm, and perforated by dorsal canals. Num- 

 erous slender, unbranched, non-pinnulate arms are borne directly 

 upon the radials, several to each of the larger plates. Cup generally 

 transversely elliptic, low and broad, expanding upwards ; dimensions 

 ranging from 3 to 27 mm. long diameter, and from 2 to 10 mm. 

 high ; number of arms from 11 to 58. 



Distribution. Devonian to latest Lower Carboniferous ( ? 

 Permian) ; Europe, America and East Indies. 

 MYCOCRINUS Schultze 



Echinod. Eifl. Kalk., 1865, p. 222. — Wachsmuth and Springer, Rev. Pal. 

 pt. 3, 1866, p. 272. — Jaekel, Crin. Deutschl., 189S, p. 55. 



Base high, protruding, at least half the total height of cup, forming 

 a solid mass pierced by nerve canals, but enclosing no cavity; con- 

 sisting of 2, probably 3, plates, which may be completely fused. The 

 three smaller RR rectilinear, except where indented at the upper 

 corners adjoining the large plates; the two large RR occupying not 

 over 65 per cent of the perimeter at the upper edge of cup ; r. post R 

 has elevated process on left shoulder for support of anal plate. 



Dimensions: Long diameter 5.4 to 11 mm.; height 3 to 5 mm.; 

 number of arms 11 to 17. 



Genotype. M. boletus Schultze. Three species ; two heretofore 

 described, and a new one proposed herein. 



Distribution. Middle Devonian ; Eifel, Germany. 



Mycocrinus boletus Schultze 



Plate I, figs, i-io 



Echinod. Eifl. Kalk, 1866, p. 222 (sep. p. no), pi. 7, fig. 4. — Wachsmuth and 

 Springer, Rev. pt. 3, p. 272. 



BB forming a prominent knob, about one-half the height and width 

 of cup ; usually divided into two plates, in one specimen into three, 

 and in one undivided. Transverse outline of cup strongly elliptic. 

 Surface smooth. Diam. 7-11 mm. ; height 3-5 mm.; arms 15-16. 



Material studied, three specimens, besides the Schultze type at the 

 M. C. Z., Harvard. NoUenbach, Priim, Kerpen, Eifel. 



Mycocrinus granulatus Jaekel 



Crinoidea Deutschland, 1895, p. 55, pi. IV, figs. 4a-c 



Like M. boletus, but surface granular, and arms 17 ; base undi- 

 vided. Diam. 5.4 mm. ; height 3 mm. Founded upon a single speci- 

 men from Priim, Eifel. 



