142 
SMITHSONIAN INSTITUTION 
and in one instance traces of the brachioles themselves are seen in place. The hydropore 
exhibits a tendency to doubling, some specimens having two pores. The surface of the plates 
is deeply sculptured into rugose ridges or folds, mostly vertical to the sutures ; the preserva- 
tion of this ornament is variable, but in several specimens it is very sharp and distinct. In the 
last three characters there are some differences from the type as described, which may be 
due to individual variation, or upon closer study may warrant the proposal of a new species. 
It is interesting to note, as bearing upon the relation of the American and European 
Silurian, that Angelin described and figured a remarkably similar form from the Wenlockian 
of Gotland,^ and referred it to the American species Lepadocrimis gehhardi Conrad. Another 
of similar type has been described from the English Silurian under the name Pseudocrinus 
quadrifasciatus, illustrated by Bather in Lankester Zoology, page 62. On the other hand 
Caryocrinus, the most prolific American type, is not represented in the European Silurian. 
Horizon and locality. Beech River formation, Encalyptocrimis zone, Niagaran ; Decatur 
County, Tennessee. 
Stribalocystites gorbyi S. A. Miller 
Plate 3S, figs. 15-18 
Stribalocystites gorbyi Miller, i8th Ann, Rep. Indiana Dep. GeoL, 1894, p. 265, pi. 2, figs. 3-8. — Bassler, 
Bibliogr. Index, 1915, p. 1209, for genus and species. 
This peculiar genus, which is said by the author to have no arms, is represented by a 
series of good specimens of this small species from the type locality. It is notable for the 
extremely small size of the tegTnen, which is composed of only 5 or 6 plates without any 
fixed plan of arrangement. Arm-facets are certainly present, though obscure, 3 to 5 in num- 
ber. Otherwise the structure is that of Caryocrinus, the folds and raised pores being in a 
variety of conditions. In general form and appearance of the calyx in a lateral view the 
species seems quite similar to Caryocrinus hulbulus. 
Horizon and locality. Laurel limestone, Niagaran ; St. Paul, Indiana. 
Lysocystites sculptus (S. A. Miller) 
Plate 33, figs. 19-22 
Lysocystites Miller, N. A. Geol. Pal., 1889, p. 259. — Bather, Treatise on Zool., 3, 1900, p. 70. — Aethocystites 
sculptus Miller, i8th Ann. Rep. Indiana Dep. Geol., 1894, p. 264, pi. 2, fig. 2 (adv. sheets, 1892, 
p. 10). — Lysocystites sculptus Foerste, Ohio Jour. Sci., vol. 21, 1920, p. 44, fig. 3. 
Originally described from imperfect material which left most of the characters in doubt. 
In 1920 Dr. Eoerste, from a study of the specimens here figured together with the types, 
worked out the plate system of this species, showing that it belongs to the genus Lysocystites 
proposed by Miller for the preoccupied Echinocystites and referred by Bather tO' the family 
Cryptocrinidae of the rare order Aporita, without pores or rhombs. The cup consists of three 
circlets of plates, the first containing 3 unequal plates, the equivalent of 5 with two pairs 
fused ; the second 5 very large elongate plates, obtusely hexagonal, and about as high as the 
first and third combined ; the third 5, pentagonal, converging to the tegmen. A prominent 
tubular fold runs from the column to each salient angle of the base, thence to the center of 
each plate of the second circlet and on to the upper corners, and from there less prominent up 
the middle of those of the third circlet. The wall of these folds is very thin, and they are 
frequently broken down, leaving open fissures ; this is especially true in the third circlet, where 
with considerable uniformity large longitudinal openings are exposed. Tbe tubular folds 
enclose diamond-sbaped areas which are traversed by low vertical striations extending up the 
middle of the plates for their full height, with transverse bands of striae from center to 
center of the large plates of second circlet. The anal opening is outside the tegmen toward the 
apex of plates of third circlet. 
1 Icon. Grin. Suecc., 1878, p. 32, pi. ii, figs. 29-35; pi. 19, figs. i8a-c. 
