144 The American Oeologist. September, 1892 
Remarks. This form was regarded by Roemer* as specifically 
identical with his Cytocriuus laevis, which comes from the same 
horizon in Tennessee, and resembles it in general form; but the 
appendages of that species are composed of single joints, and it 
has a smaller number of interbrachials. 
Melocrinus parvus W. and Sp. (nov. spec.) 
A small and very slender species of the type of Mdocrinvs 
Roemeri, having, like that species, five uniserial appendages giving 
-off the arms. Dorsal cup ob-pyramidal, the interradial spaces 
deeply depressed, and the cross-section at the top of the costals 
distinctly pentalobate. The plates a little convex, and covered 
with obscure ridges. 
Basal cup almost cylindical, its upper end slightly wider, the 
lower face completely covered hy the column; the plates as high 
as the radials, and the interbasal and basi-radial sutures dis- 
tinctl}' grooved. Radials a little higher than wide. First costals 
of the same proportions as the radials. Second costals smaller, 
proportionally shorter, and irregularly axillary ; one of their upper 
faces shorter and giving otf an arm, the other forming the base of 
the free ray, which necessarily was uniserial. Interbrachials three 
at the regular sides, four at the anal side, the latter having three 
plates in the second row against two at the other sides. Ventral disk 
convex, the interambulacral spaces a little depressed; composed 
■of moderately large, slightly convex plates. Anus excentric. 
Horizon and Locality: Niagara group, St. Paul, Ind. 
Type in the collection of Wachsmuth and Springer. 
Remarks. This species differs from M. roemeri in the nar- 
rower and less spreading base, in the proportions of the radials 
and costals, and in the convexity of the plates. 
NOTES ON A COLLECTION OF FOSSILS FROM THE 
LOWER MAGNESIAN LIMESTONE FROM 
NORTHEASTERN lOWA.t 
By S. Calvin. Iowa City. 
Until recently we have been accustomed to regard the Lower 
Magnesian limestone of the Upper Mississippi valley as destitute 
•of organic remains. Dr. White in his report on the Geology of 
Iowa, Vol. I, pp. 173-174, says that "the only fossils that have 
*Silur. Fauna West. Tenn., i860, p. 46. 
tFromthe Bulletin of the Laboratories of the State University of Iowa. 
