626 STUART WELLER 
surface of the plates, its diameter about one-third that of the under- 
basal disk. Basal plates large, all except the posterior one hexag- 
onal but with the two proximal faces in nearly a straight line and 
together about equal in length to each one of the other sides so that 
the general outline of the plates is nearly regularly pentagonal, the 
height and width of each of these plates in the type specimen is 
about 24™™; the posterior basal is not complete in the type specimen 
but it is probably similar to the others except in being somewhat 
wider and in having the distal angle truncated for the reception of 
an anal plate. Radials large, pentagonal, wider than high. Anal 
plate not present in the type specimen, probably quadrangular or 
pentagonal in outline and resting upon the truncated distal end of 
the posterior basal between the two posterior radials. 
Remarks.—Unfortunately the type and only specimen of this 
species 1s imperfectly preserved and somewhat distorted, so that it 
is not possible to give accurate measurements. The posterior side 
has been destroyed by weathering so that it is not possible to be 
certain in regard to the form and position of the anal plate. It is 
certain, however, that no radianal plate is present in the calyx, 
but the presence of a small anal plate is more than probable. 
The posterior basal is broader than any of the other plates 
of the basal ring, and the two posterior radial plates when pro- 
jected posteriorly to a width equal to the width of the remaining 
radials leave a space of about 7™™ to be occupied by an anal 
plate. 
The nearest allies of the species are found in P. princeps Eth., 
and P. konincki Clarke, from the upper marine series of the Permo- 
Carboniferous of New South Wales.‘ It differs from P. konincki 
in the convex rather than concave underbasal disk, and from P. prin- 
ceps it differs in its flatter plates with less deeply impressed sutures. 
From both of these Australian species it differs in its smaller size. 
In general form the species resembles Ulocrinus blairi M. & G., 
but it may be easily distinguished by the absence of the radianal 
plate which is very large in that species, and by the relatively broader 
underbasal disk. 
t Mem. Geol. Surv. N.S. W., “Paleontology,” No. 5, Part 2, pp. 107-10 (1892). 
