MELOCRINID&. 299 
known, composed of rather small pieces. Form and position of anus un- 
known. Column round, strong; the nodal joints projecting, the intervening 
ones knife-like. 
Horizon and Locality. — Hamilton group; Canandaigua Lake, N, Y. 
Type in the collection of Prof. J. M. Clarke, now in the State Museum at 
Albany. 
Melocrinus Tiffanyi W. and Sp. (noy. spec.). 
Plate XXII. Figs. 7a, b. 
Calyx pyriform; the sides nearly straight from the top of the basals to 
near the bases of the arms; the tegmen depressed-hemispherical ; cross- 
section, as seen from above, obtusely pentangular. Surface of plates orna- 
mented by faint ridges, radiating from near the centre of the plates to the 
centre of adjoining ones. 
Basals projecting laterally, forming four conspicuous, elongate nodes ; 
the lower part somewhat excavated for the reception of the column. Radials 
and costals gradually decreasing in size upwards, about as long as wide; the 
second costals not more than half the size of the radials. Of the distichals 
two plates are preserved; the lower one fully one half smaller than the 
preceding axillary; the second short, shaped like an arm joint and curving 
outwards. There are no interdistichals, all plates of the arm trunks being in 
contact laterally. Interradial areas on a plane with the radials and costals ; 
the first interbrachial the same size as the radials, and followed in the type 
specimen by two plates at three of the sides, but in the posterior and right 
antero-lateral interradius by three, and these by numerous rows of from 
three to four plates, which connect with the disk pieces. Ventral disk 
depressed-hemispherical, the plates very uniform, rather large, having the 
size of the third row of interbrachials. They are ornamented like the plates 
of the dorsal cup, but are a little more convex. There are apparently no 
orals. Anus excentric, probably connected with a tube. Arms unknown ; 
column round. 
Horizon and Locality. — Hamilton group; New Buffalo, Iowa. 
Type in the collection of Mr. S. A. Tiffany of Davenport. 
