156 ECHINODERMATA—PELMATOZOA 
SUB-KINGDOM III 
Cyathocrinus, Miller, emend. W. and Sp. (Figs. 259, 260). Dorsal cup 
IB five, equal. large; the posterior 
cup-shaped, bilaterally symmetrical. 
one truncated for the support of an anal plate. 




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Fig. 260. 
a, Cyathocrinus longimanus, Ang. Silurian ; 
Gottland. Crown of the natural size (after 
Angelin); b, C. ramosus, Ang. Portion of an 
arm viewed from the side; e, Ventral aspect of 
same (enlarged); d, C. malvaceus, Hall. Sub- 
Carboniferous ; Burlington, Iowa. Tegmen 
perfectly preserved; e, The same after removal 
of the covering pieces and orals (after Meek and 
Worthen). 
ft five, all simple ; their upper 
faces provided with a facet occupying less 
than the full width of the plates. Ventral 
sac rarely extending to more than one-half 
the height of the arms. 
The number of 
costals extremely variable among the rays. 
Arms rather delicate, composed of elon- 
gatecylindrical joints, and giving off numer- 
ous branches, most of which divide again. 
Column round. Ordovician to Sub-Car- 
boniferous ; Europe and North America. 







Homocrinus curtus, Mull. sp. 
Devonian ; Schonecken, Hifel. 
a, Calyx from the anal side, showing 
ventral sac and one arm (right and 
left sides reversed); b, Stem; c, Face 
of stem-joint (after Schultze). 

Fic. 259. 
Cyathocrinus. Diagrain of dorsal 
cup (after Bather). 
Lecythocrinus, 
Miiller, emend. 
Zittel (Figs. 
225, 261)" 
Like the preced- 
ing, except that 
the infrabasals 
are very small, 
and entirely 
concealed — by 
the — column. 
Ventral sac in 
the form of a 
long tube, and 
composed of 
numerous, very 
regularly — ar- 
ranged — hexa- 
gonal plates. 
Column _ ob- 
tusely — quad- 
rangular, com- 
posed of long 
joints, and perforated by a large central and four peripheral canals. 
Devonian ; Eifel. 
Gissocrinus, Ang. (Fig. 262). 
truncated, and supporting an anal plate. 
IB three to five. 
B five; the posterior one 
Radial facets elliptical in contour. 
Ambulacra roofed over by alternately arranged covering pieces. Ventral 
Madreporite well defined. Arms long, 
regularly bifurcating. Silurian; Gottland and England. Devonian; Eifel. 
Arachnocrinus, M. and W. Calyx very small, resembling Cyathocrinus in 
the arrangement of its plates, but forming a bulbous protuberance from which 
sac long, always laterally folded. 
the robust arms stretch out horizontally. 
North America. 
Silurian and Devonian ; Europe and 
1 [The type-specimen upon which this genus was founded (ZL. Hifelianus, Miill.) was regarded 
by Schultze as an abnormal variety of Zauxocrinus, and the specific name was changed by him to 
T. briareus. But Taxocrinus has no such ventral tube, nor has it peripheral canals. In the latter 
respect Lecythocrinus differs also from Gissocrinvs, with which it otherwise has close affinities. ] 
