434 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Horizon and Locality. — Upper Burlington limestone ; Burlington, Iowa. 
Remarks. — This species was described by McChesney as having but four 
plates in the anal interradius, and three at the other sides. In that case the 
type specimen was a very young example, in which the upper plates between 
the rays were as yet undeveloped. 
LOBOCRINUS W. and Sp. (nov. gen.). 
(AoBds a lobe; kpivov, a lily.) 
Form of the calyx from pyriform to wheel-shaped; the rays more or 
less distinctly lobed, and the arms arranged in groups; the ventral disk 
high, conical or bulging. Plates convex, smooth, or ornamented. Basals 
three, rather large, forming a subcylindrical cup, which is thickened at the 
lower end. MRadials larger than both costals together; the second costals 
frequently smaller than the first. Arm facets subcircular, concave, and in 
some species provided with a transverse imperforate ridge. Arm openings 
large, directed upward. There are no traces of respiratory pores, but they 
may have been located close to the edges of the ambulacral openings, some 
of which are a little excavated at one side. Arms one to each opening; 
short, cylindrical, and biserial from the base up. Pinnules long.  Inter- 
brachials numerous, and in contact with the interambulacrals. Some species 
have interdistichals. Anal plate succeeded by two interbrachials with a sec- 
ond anal between them, and two or three additional rows of from two to 
three pieces. The ventral disk is generally large, the anal tube central, 
stout and very long. Orals well defined, being larger and more nodose than 
the surrounding plates, especially the posterior one, which is erect, and forms 
the base of the anal tube at the anterior side of the tegmen. The radial 
dome plates are large and quite prominent. Column stout, round, and com- 
paratively long; axial canal small and pentangular. 
Dnstribution. — Lobocrinus, so far as known, occurs only in America, and 
is restricted to the Burlington and Keokuk groups. 
Type of the genus: Lobocrinus Nashville (Troost). 
Remarks. — Most species of this genus were originally described under 
Actimocrinus, but were afterwards referred by Meek and Worthen to Bato- 
ermus, and one of them to Uperocrinus. The latter name had been proposed 
as a subgenus of Actinocrinus with “ Actinocrinus ( Uperocrinus) pyriformis” as 
type. By placing these species under Batocrinus, we should have to ignore 
the principal character upon which that genus was founded, for in all of 
a 
