Tod THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
like protuberance, or at the outer end of a short conical tube. Column 
4 
\\ an round; axial canal minute. 
| LDstribution. — This genus is largely represented in, and nearly to the 
close of, the Carboniferous, both in America and Europe; but not a solitary | | 
species is known from the Devonian, nor from the Coal measures. 
Lily cag 
SS ea eee 
ig Type of the genus: Dichocrinus radiatus Minster. | 
+H] _ Remarks. — There has been some difference of opinion as to the number 
of “primary radials” in Dichocrinus. The Austins represent their D. fusi- 
JSormis* with three costals, and De Koninck and Le Hon, in their generic 
formula, fix the number of “primary radials” at four, on the strength of 
Austin’s figure. Shumard, on the other hand, describes two of his species, 
D. cornigerus and D. sexlobatus, with a single large radial followed directly 
ia by the distichals. Casseday and Lyon give the ntimber of “radials’”’ as one 
| to three, and with this Meek and Worthen agree. | 
From a careful examination of extensive material, we are convinced that | 
all species of Dichocrinus have three so-called radials, 7. e. two small costals : 
above the radial, united by syzygy; but that D. cornigerus, D. seulobatus, 
and the other species for which we proposed the genus Talarocrinus, have 
but one, and this so extremely small that it was overlooked by Shumard. 
The genus Cotyledonocrinus Casseday and Lyon is based on incorrect 
observation. Hxamination of the type specimens shows that CO. pentalobus, 
the type of the genus, has two basals, followed by a ring of six plates, and 
not by five as described by the authors. 
Dichocrinus lachrymosus Hatt. 
Plate LXX VII. Figs. 2a, b, c. 
Dl | 1859. Dichocrinus lachrymosus —Hatu; Suppl. Geol. Rep. Iowa, p. 84; figured Bull. I. N. Y. State 
He | | Museum of Nat. Hist., Plate 2A, Fig. 11. 
ie | | 1881. Platycrinus subspinulosus — W. and Sp.; Revision Paleocr., Part ET; p75 
ie 1885< Dichocrinus lachrymosus — W. and Sp.; ibid., Part IIL, Oe IIE), 
A rather large and grotesquely ornamented species. Calyx large in | 
proportion to the size of the arms, broadly conical, as wide as high; sides 
rapidly and uniformly spreading from the base of the basal cup to the base 
of the brachials; the radials rounded on the back, producing angular depres- 
sions along the suture lines. Surface of plates covered by series of prominent 
wart-like processes of abrupt and irregular form, those of the same plate 
ae being generally confluent. On the basal cup, these processes occupy the 
APE lower end, there being two or three of them to each basal, each set separated 
* Ree. and Foss. Crin., Plate 5, Fig. 62. 
