ACTINOCRINID ZA. 635 
the disk and tube quite irregular in form, size, and arrangement, almost 
as flat as those of the cup, and growing smaller as they approach the 
arms. Column apparently stout, the axial canal large and pentangular. 
Horizon and Locality. — Upper Burlington limestone, Burlington, Iowa. 
Type in the Museum of Comparative Zodlogy, Cambridge. 
Teleiocrinus adolescens W and Sp. (nov. spec.). 
Plate LIX. Fig. 4. 
(?) Syn. Actinocrinus penicillus —Mxrx and WortueEn, 1873, Geol. Rep. Illinois, Vol. V., p. 342, Plate 8, 
Fig. 2. 
Intermediate between Cactocrinus and Teleiocrinus, but nearer the latter. 
Calyx moderately large, the height of the dorsal cup greater than the width 
at the rim, the sides gradually rising to the top of the distichals, then curv- 
ing abruptly outward, forming a rim, which is somewhat interrupted at the 
interradial spaces from the palmars up. Plates thin and slightly convex, 
traversed by angular, well defined ridges passing from plate to plate, and 
forming numerous triangles. The ridges are single, except between the 
basals and radials, which are united by two or three. They meet at the 
middle of the plates in conspicuous tubercles, which are surrounded by 
several small nodes, placed within the corners of the triangles. 
Basals of moderate size, their ridges thickened at the lower end, and 
formed into angular processes, which project downward and rest against the 
margins of the two upper stem joints. Radials larger than both costals 
together, as long as wide or a little longer; the first costal hexagonal, 
the second generally somewhat smaller and heptagonal. Distichals as large 
as the costals; both axillary, giving off from the outer side of the ray 
an arm, which is free from above the second plate, and from the inner the 
second axillary. ‘This is followed by three more axillaries, of which the two 
lower ones, respectively, support again an arm at one side, the upper two 
arms; there being five arms in each main division, and ten to the ray. The 
brachials forming the rim are sharply angular on the back, and separated 
longitudinally by deep grooves. Arms somewhat flattened, quite smooth on 
the outer faces, but their lateral margins slightly serrated. Regular inter- 
brachials: 1, 2, 2,2, 1; the upper very narrow, and sometimes touching the 
plates of the tegmen. Anal plate followed by 2, 3, 3, 8, and 2 plates. Inter- 
distichal areas wide and deeply depressed, occupied by two plates, longitudi- 
