300 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
Melocrinus Calvini W. and Sp. (noy. spec.). 
Plate XXII. Fig. 6. 
Similar to the preceding species, but the sides of the dorsal cup convex, 
and the general form of the calyx subovoid; the basals less projecting; the 
radials, fixed brachials and interbrachials — the latter to the third row — 
crowned by a large, rather conspicuous rounded node without other orna- 
mentation; the upper interbrachial and interambulacral plates a little 
convex. 
Basals projecting laterally, and forming four rather conspicuous nodes 
around the columnar attachment which is a little projecting. Radials and 
costals longer than wide. The distichals of the same ray in contact laterally. 
Regular interbrachial spaces large, but slightly depressed between the arm 
trunks; the plates arranged: 1, 2, 3, 5, the upper ones insensibly connecting 
with the plates of the ventral disk. Anal interradius widest, having three 
plates in the second row. Ventral disk short; the plates rather small and of 
uniform size; orals apparently unrepresented. Anus excentric, probably at 
the end of a narrow tube. 
Horizon and Locality. — Hamilton group; Johnson Co., Iowa. 
Type in the collection of Prof. 8. Calvin of Iowa City, in whose honor 
this rare species is named. 
Melocrinus oblongus W. and Sp. (noy. spec.). 
Plate XXII. Figs. 9 and 12. 
A rather slender species of less than medium size. Dorsal cup obconical ; 
the sides straight to the top of the second costals, whence the rays turn out- 
ward and form distinct lobes around the calyx, which give to the section 
a decidedly pentalobate outline. Plates convex, a little nodose, but without 
ornamentation. 
Basals small, subequal, notched at the sutures; the lower face but slightly 
truncate, and very little excavated. Radials and first costals generally 
longer than wide, especially the former; the second costals often as wide 
as long. Distichals 2X 10, the two upper ones axillary and separated by 
a small interdistichal. The arm trunks not preserved in the specimens, but 
as there are two distichals, the trunks must have been formed of two rows of 
plates. The first interbrachial as large as the first costal; succeeded by 
