Camerate Crinoids. — Wachsmuth and Sprincjer. 143 
Horizon and Locality: Niagara group; associated with Astrae- 
ospongia meniscus. Decatur Co. . Tenn. 
Type in the collection of \yachsmuth and Springer. 
Remarks. Roemer described this species as Cytocrinus laevis, 
making it the type of a new genus. He supposed it had three 
basals, and he did not understand the arm structure, which is 
evidently that of Milocrinns. We refer the species to the latter 
genus, but are compelled to change the specific name, as already 
Goldfuss in 1826 described a Melocrinus laevis from the Eifel, 
and replace it by Melocrinus Roemeri. Roemer originally in- 
cluded in this species two forms, the typical one from the Niagara 
group of Western Tennessee, and another from the same horizon 
of Louisville. The latter has been described by us as Melocrinus 
ohlongus. The two species resemble each other in form, but M. 
ohlongus is considerably larger, the calyx contains many more 
plates, and the tubular appendages giving off the arms are com- 
posed of two rows of brachials in place of one. 
Melocrinus oblongus W. and Sp. (nov. spec.) 
A rather slender species of less than medium size. Dorsal cup 
bbconical; the sides straight to the top of the second costals, 
whence the rays turn outward and form distinct lobes around the 
calyx, which give to the section a decidedly pentalobate outline. 
Plates convex, a little tumid, 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 2x10; the two 
upper axillary and separated by a small interdistichal. The tubu- 
lar appendages not preserved in the specimens, but, ' as there are 
two distichals to each ray, they obviously were biserial. The 
first interbrachial as. large as the first costal, succeeded by rows of 
two, three, three, and three plates, which meet the interaml)ulac- 
rals. Anal interradius a little wider, with three plates in the 
second row, and four in the third. Ventral disk low, irregularly 
convex; the ambulacral spaces slightly elevated; the plates — 
orals included^almost of uniform size. Anus subcentral, at the 
end of a tube. 
Horizon and Locality: Niagara group; near Louisville, Ky. . 
and St. Paul, Ind. 
Types in the collection of Wachsmuth and Springer. 
