148 ECHINODERMATA—PELMATOZOA SUB-KINGDOM III 
numerous, and enclosing supplementary anals, which sometimes form a con- 
tinuous series. There are also numerous interdistichals, and frequently 
interpalmars, which form conspicuous depressions between the arm-plates. 
Tegmen low, composed of minute irregular pieces ; anus eccentric. Arms ten 
to twenty, branching in the free state, long, slender, and 
uniserial. Column round, or exceptionally pentangular. 
Ordovician ; North America. 
Stelidiocrinus Ang. (Harmocrinus, Ang.) Form of dorsal 
cup as in the preceding, but the JR fewer and much larger, 
and plates generally without ornamentation. Plates of the 
tegmen also comparatively large. Arms uniserial, sometimes 
interlocking. Silurian ; Europe and North America. 
Macrostylocrinus, Hall. B three, unequal. Anal interradius 
much wider than the others; its first row of Jf consisting of 
ee. two interbrachials separated by a supplementary anal. The 
Glyptocrinus deco. first row in the four other interrays consisting of a single 
See aain Ordo- interbrachial. Arms ten, simple, and biserial. Silurian; North 
Group) ;_ Cincinnati, America. 
ease Allocrinus, W. and Sp. £B three, unequal. Interbrachials 
few, longitudinally arranged. Arms uniserial. Silurian ; North America. 
Dolatocrinus, Lyon (Cacabocrinus, Hall). Dorsal cup perfectly pentamer- 
ous, cup-shaped or saucer-shaped. #8 primitively three, but completely 
anchylosed in the adult. Costals two; interbrachials few, the first ones 
extremely large. 'Tegmen comparatively flat, and composed of rather large 
plates, of which the orals form the summit. Anus at the end of a short tube. 
Arms biserial; generally branching. Devonian; North 
America. 
Stereocrinus, Barris. Like the preceding, but the 
anchylosis of the B incomplete, and with only one costal. 
Hamilton Group ; North America. 

Family 9. Calyptocrinidae. Angelin. 
Base monocyclic. Lower brachials and interbrachials form- 
ing an important part of the dorsal cup, which is perfectly penta- 
merous. Plates of the calyx limited to a definite number. 
Basals four ; radials five, in contact all around ; costals 2 x 5 ; 
distichals two, and palmars 2 «10, of small size. Arms 
twenty, resting in compartments formed by partitions attached 
to the teymen. Silurian and Devonian. 

Eucalyptocrinus, Goldf. (Figs. 251, 252). Calyx with a 
deep concavity at the lower end, the 6 forming the bottom, Fia. 251. 
and the F& the sides of an inverted cup. Supplementary | Lucalyptocrinus reqularis, 
A Patt . Hising. sp. Silurian ; 
pieces of the calyx consisting of 1 x 2 interbrachials, and  Gottiana. P Crowd Beh 
nO 7 sasatarphal » F ~~ : — « =, ap. arms removed from one 
one interdistichal ; the latter of the same form as the inter- {ay"in order to show the 
brachials, and nearly as large as the two upper ones picks in which they 
. pled repose. 
combined. ‘Tegmen elongate, its upper part extended 
to forma tube. It is composed of five ranges of plates, of which the two 
middle ones are the least regular in their arrangement, and the upper one 
fo) oD ’ 
closes the centre. Attached to the outer walls of the tegmen, and extend- 
