174 ECHINODERMATA—PELMATOZOA SUB-KINGDOM III 
angles of the stem. Arms moderately branching. Cirri generally directed 
upwards ; those of Pentacrinus, as a rule, downwards. Recent; Pacific Ocean. 
Extracrinus, Austin. Base composed of five rudimentary JB and five B ; 
radials with downward prolongations from their lower ends. The five inter- 
radial petals on the upper and lower faces of the stem-joints narrower and 
more lanceolate than in Pentacrinus. Lias to Recent. 
(2?) Balanocrinus, Ag. Stem-joints round, with serrated margins ; articular 
faces marked by five crenulated ridges radiating from the centre. Lias to 
Cretaceous. 
Family 9. Comatulidae. d’Orbigny.! 
Pedunculate and fixed in nepionic stages, later losing the stem and leading a free 
existence. Buse psewlomonocyclic ; infrabasals visible only in the ciliated larva, 
afterwards becoming fused with 
the top stem-joint.  Basals, 
which are large in the larval 
condition, are transformed at 
the end of the Pentacrinoid 
stage into the so-called rosette. 
Centrodorsal giving off numer- 
ous cirri after detachment of 
the stem; its angles inter- 
radially disposed, like the stem 
of dicyclic Crinoids. Tegmen 
coriaceous, naked or indurated 
by thin calcareous plates. 
Body - cavity very shallow ; 
arms simple, interlocking, 
pinnulate. Lias to Recent. 
Over 200 species are 
represented in the present 
seas, most of them being 
inhabitants of — shallow 
water. 
Antedon,  Fréminy. 
(Alecto, Leach ; Comatula, 
Lam.; Pterocoma, Ag. ; 
Decacnemos, Bronn ; Comatu- 
lina, @Orb. ; Hertha, Hage- 
Fra. 201. now ; Solanocrinus, Gleno- 
a, Antedon (Solanocrinus) costatus, Goldf. Upper Jura (Diceras- tremites, Goldf.), (Figs. 235, 
Kalk); Kelheim, Bavaria. Dorsal aspect of crown; centrodorsal and is 
pinnules not preserved (slightly reduced) ; b-d, A. scrobiculatus, Goldf. 291 ): Mouth centr al, anus 
eccentric; centrodorsal 
Upper Jura; Streitberg, Franconia; b, Ventral; c, dorsal; and 
d, lateral aspect of calyx; e, Arm-plate. 
button-shaped. Costals 
two; the upper one axillary. Arms ten or more. Lias to Recent. 
Eudiocrinus, Carp. (Ophiocrinus, Semper). Like Antedon, except that it 
has only five arms. Represented by one Neocomian and five Recent species. 
1 Miller, J., Ueber die Gattung Comatula, ete. (Abhandl. Berlin. Akad.), 1847. 
Ludwig, H., Beitrige zur Anatomie der Crinoideen (Zeitschr. fiir wiss. Zool. XXVIII), 1877. 
Carpenter, P. H., Report on the Crinoidea (Sci. Results, Chall. Exped., XI. and XXVI.), 1884-88. 
Jaekel, O., Entwurt einer Morphogenie und Phylogenie der Crinoideen (Sitzber. naturf. Ges.), 1894. 

