12 



BULLETIN 115, UNITED STATES NATIONAL MUSEUM. 



The type and only species of the genus is typically of large size, 

 with calyx shallow and broad, the average diameter of three speci- 

 mens being about 10 cm. 



Ilo'nzon and locality. — Onondaga (Sellersburg) limestone: Louis- 

 ville, Kentucky. A fragment belonging to the genus, and perhaps 

 to the type species, has been found in Erie County, western New 



York. 



HIMEROCRINUS, new genus. 



HIMEKOCRINUS PLENISSIMUS (Lyon). 



Plate 2, figs. 2; plate 3, figs. 1-4; plate 4, figs. 1-4. 



Hadrocrinus plenissivius Lyon, 1869, Trans. Amer. PhUos. Soc, vol. 13, p. 445, pi 

 26, figs. 6 1, 6 2, 6 3. — Wachsmuth and Springer, 1897, North American 

 Crinoidea Camerata, p. 328, pi. 24, figs. 2 a, b. — Rowley in Greene, Contrib. 

 Indiana Paleontology, vol. 1, 1903, p. 165, pi. 48, figs. 5, 6. 



Fig. 5.— HIMEROCRINUS. 



//// = i Br; \\\\ = i II Br; ^ = i III Br. 

 Dotted line = R R and Br. 



The genus is founded on Hadrocrinus ylenissimus of Lyon^, which 

 is the only known species. It attains a very large size, one of the 

 largest of known Camerata, upwards of 20 specimens ranging from 

 10 to 15 cm. diameter of calyx. From a deep inverted cone involving 

 the basals and radials — which are both large — the wall spreads out- 

 ward in a graceful reversed curve to the arm bases, forming a broad, 



•Araer. Philos. Soc, vol. 13, 1869, p. 445, pi. 26, Hgs. 6 1, 2, 3. 



