MELOCRINID.E. 273 
which he afterwards proposed the genus Pycnocrinus, are young examples of 
Glyptocrinus Dyert. The specimens have variously from nine to twelve dis- 
tichals, but in place of having six to eight of them incorporated into the’ 
calyx, only one or two are calyx plates, the others being free. That the 
specimens are comparatively smaller, the column stouter, the basals propor- 
tionately larger, the interbrachials and interdistichals less numerous, the 
arm joints higher, the pinnules stronger and placed farther apart, all indicate 
a less mature stage of individual growth, a phase through which every 
Glyptocrinus must naturally have passed. 
Miller defines Pyenocrinus as follows: “Calyx cup-shaped. Column 
round. Basals five, small, pentagonal. Primary radials 3 x 5.  See- 
ondary radials none. Regular interradials three. Arms ten, but some- 
times dividing after becoming free. Pinnules dense and strong.” This 
description would apply equally well to any young Glyptocrinus. It must be 
remarked, however, that both of Miller’s types have small interdistichals, 
which he overlooked. The presence of these plates proves conclusively that 
at least one of the distichals takes part in the calyx, and that “secondary 
radials” are not unrepresented in those specimens, as Miller supposed. 
Horizon and Locality. — Found associated with the two preceding species 
at Cincinnati and other places. 
Type in the collection of 8. A. Miller. 
Glyptocrinus ramulosus Bitiincs. 
Plate XX. Figs. da, b. 
1856. E. Brtres; Canadian Naturalist and Geologist, No. 1, p. 54; also Geol. Surv. of Canada (Rep. of 
Progress), 1857, p. 258, and 1859, Decade IV., p. 57, Plate 7, Fig. 2a and Plate 8, Fig. 1. 
1881. W. and Sp.; Revision Paleocr., Part II., p. 189. 
1883. §S. A. Mitten; Journ. Cincin. Soe., Nat. Hist., p. 224. 
A large species. Dorsal cup obconical, somewhat rounded at the base. 
Costals and distichals remarkably uniform in size; also the palmars propor- 
tionally large. Plates almost flat and without any markings, except a con- 
spicuous, obtusely angular ridge passing up the rays, occupying nearly one 
half their width. 
Basals small, only the upper angles visible from a side view. Radials 
somewhat larger than the costals, as long as wide. Distichals six, exception- 
ally seven; the proximal one as long as the costals, but a little narrower ; 
the succeeding ones smaller. There are fixed pinnules from the second, 
35 
