108 
of the radial plates forbids a reference to that genus. In Cijatliocrinns the 
articular facets seldom occupy more than one-half tlie width of the plates, 
and sometimes less. Eurthermore, in some of the American species, now 
placed in Thkdocrlnus, and referred to Graphiocrhms hy Wachsmnth and 
Springer, the first two, or in’oximal plates of the “ ventral tube,” or “ pro- 
boscis,” rest on the anal plate, as they do in the present case. The impres- 
sions of these proximal plates are distinctly visible in the side view of 
De Koninck’s large figure,^ and are referred to hy him as anals ; but so far I 
have only been able to distinguish one of these in the specimens before me. 
JPhialocrinus Koninchi is only known to me in the form of internal 
casts. In this condition, the base on which the calyx would otherwise rest 
(PI. XVI, I’ig, 1) is represented by a depression of. variable depth and width, 
but usually of considerable proportions, in which the five infra-basals would 
lie. This marked dorsal hollow is very characteristic of the species, and all 
specimens from the chief locality yielding P. Koninchi, Nowra, in the 
Shoalhaven District, exhibit it. The calyx, in this condition, when placed in 
its natural position rests as near as possible on the inter-basi-infra-basal 
sutures, and, in consequence, the infra-basal plates are invisible in a side 
view. It not infrequently happens that specimens from the Xowra Grit arc 
more or less pressed out of shape, a fact which should always be taken into 
consideration when comparing them with others from different localities. 
I was for some time doubtful as to the relations of Vhialocrinus 
Koninchi to P. princeps, whether or no the basal hollow of the latter, when 
in the condition of casts, Avould be entirely filled by the plates in situ. I 
have, however, come to the conclusion that such would not be the case, and 
that the two forms are quite distinct, separated by the combined form of their 
rcspectii^e infra-basal plates. With neither of the other species need P. 
Koninchi be compared. 
Prof, de Koninck suggested the identity of the bodies described by 
Prof. J. D. Dana in the Geological Deport of the “ United States Exploring 
Expedition,” under Commodore Charles Wilkes, U.S.X., as Idcntudia coroned, 
with the basal plates (his sub-radials) of the present species. Dc Koninck 
remai’ked® : — “ In carefully examining each sub-radial impression, one can 
easily see five folds, faintly indicated, springing from a common central, 
1 Foss. Pill. Nouv.-Galles du Sud. Pt. 3, 1877, t. G, f. 4. 
Wilkes’ U.S. Explor. Exped. , 1849, X (Geology), p. 713. 
® Foss. Pal. Nouv.-Galles du Sud, 1877, Pt. 3, p. iC5. 
