OGTy, 1907, NEw CRINOIDS — SLOCOM. 301 
cup accompanied by a natural mold of which a part of the base 
is missing. . 
Locality: Niagaran limestone of the spoil heaps along the Chicago 
Drainage Canal near Lemont, Illinois. 
Family CALYPTOCRINID. 
EUCALYPTOCRINUS Goldfuss. 
EUCALYPTOCRINUS OBCOoNICUS' Hall, Plate LXXXVI, Figures 1-2. 
1867 F. obconicus Hall, 20th Rept. N. Y. St. Mus., p.*323, Pl. XI, 
Pio. A’. 
1870 FE. obconicus Hall, 20th Rept. N. Y. St. Mus., Rev. Ed., 
(Bids oF ob ield ed beat; GS Exel ai ks ees om § 
1885 E. obconicus Wachsmuth & Sp., Rev. Paleocr. Pt. III, p.133. 
1897 E. obconicus Wachsmuth & Sp., N. Am. Crin. Cam., Vol. 
Ieepesesy tt lola NX XI LE Fioxrs. 
1900 FE. obcontcus Weller, Bull. 4, Nat. Hist. Surv., Chicago Acad. 
SCL ep oon Vi shis.38: | 
Dorsal cup obconical, truncated at the base by the attachment for 
the column; height nearly twice its diameter at the arm bases; grad- 
ually and regularly expanding from the size of the column at its base 
to the arm bases where it attains its greatest diameter. The plates 
are thicker in the central portion than at the edges, so that both their 
inner and outer surfaces are convex. The outer surface of the plates 
is smooth and slopes gently towards the sutures. The natural cast is 
similar in outline to the exterior of the dorsal cup, but it is pointed at 
the base. The position of the sutures is indicated by low angular ridges 
which are formed by the convexity of the inner surface of the plates. 
Basals four, three pentagonal, one hexagonal, long and narrow. 
Together they form a cup, height and width about equal. Radials 
five, the largest plates in the calyx; four heptagonal, the other hexag- 
onal, about equal in size and nearly twice as high as wide. First cos- 
tals quadrangular, higher than wide, proximal and lateral edges arched, 
distal edges much narrower than the proximal ones. Second or axial 
costals are in the form of a regular pentagon, somewhat smaller than 
the first costals. Distichals fourtoeachray. The first pair hexagonal, 
in contact with each other and about the size of the second costals 
upon which they rest. The second pair is very small. First inter- 
brachials ten-sided, about twice as high as wide and next to the radials 
in size. These are followed by two long narrow plates, with their 
longest edges in contact. Interdistichals small, angular below and 
