CYATHOCRINIDAE 
137 
tive specimens to Dr. Bather at the British Museum, requesting his opinion on the tentative 
identification I had made. His answer was that upon first looking at the picture, before 
reading anything I had written about it, he had said Gissocrinus,” but without knowing why. 
So in view of our scant knowledge concerning the structure of the calyx, these two concur- 
rent guesses will have to be taken as the chief authority for the generic reference. 
The most remarkable feature of the species is the small oval connecting plates at the 
brachial articulations, sometimes two, or even three, in succession, and located precisely where 
the food grooves, whether one or two, cross the faces of the brachials ; they are not confined 
to the dorsal side, but extend entirely through to the interior, where they are equally promi- 
nent, as is beautifully shown by figure 6. I know of nothing else like them in crinoid mor- 
phology. The term “ patelloid plates ” which I have applied to them will doubtless recall the 
term as used by Hall for some supposed intervening plates connecting successive brachials in 
Forbesiocrinus and other genera ; but those, as I have shown at length in the Flexibilia mono- 
graph of 1920, pages 44, 1 12, 239, etc., are not plates, but only superficial processes from 
the proximal face of brachials at the dorsal side, which sometimes get broken off and thus 
may resemble plates. This crinoid must have been of fragile construction, as indicated by 
the extreme thinness of the wide-spreading brachials ; this is well shown by figures 3 and 6, 
where several of them are seen superimposed in two or more layers. They recall the paper- 
like calyx plates of Uintacrinus. 
Florizon and locality. Beech River formation ; Tuck’s Mill, Decatur County, Tennessee. 
Gissocrinus approximatus new species 
Plate 32, figs, y-p 
Fragmentary brachials found at St. Paul indicate that forms similar to 
the last exist in the Laurel limestone, with an important difference in the ap- 
parent absence of the patelloid plates. We have isolated axillary brachials with 
food-grooves both open and covered, as figured, one of them of even greater 
length than in the Tennessee specimens. 
Horizon and locality. Laurel limestone ; St. Paul, Indiana. 
Gissocrinus quadratus new species 
Plate 32, figs. 10, ii 
I figure under this name an axillary plate and the two following it which 
are nearly rectangular, and clearly devoid of any patelloid plates, and also a series 
of nearly square plates with the food-grooves covered. No other parts of this 
or the preceding species were found, but their occurrence is important as evi- 
dence of the wide distribution and variable nature of this peculiar type. 
Horizon and locality, same as last. 
Botryocrinus tenuidactylus new species 
Plate 31, fi.g. p 
Botryocrinus Angelin, Icon. Crin. .Suecc., 1878, p. 24. — Wachsmuth and Springer, Rev. Pal., i, 1879, p. 97; 
3, 1886, p. 191. — Bather, Ann. Mag. Nat. Hist., 7, 1891, p. 392; ibid., 9, 1892, p. 189; Treatise on 
Zool., 3, 1900, p. 113, figs. 21, 179. — Zittel-Eastman, Textb. Pal., 2d ed., 1913, p. 221. — Bassler, 
Bibliogr. Index, 1915, p. 130. 
This genus is chiefly distinguished from the Cyathocrinidae by its mode 
of arm-branching, which is mostly of the heterotomous type, the rays dividing 
