142 RECENT UNSTALKED CRINOIDS 
the columns are closely crowded; each radial area has 
three columns of cirrus-sockets, the two outer of four each, 
the median of two only; but the sockets are so crowded 
that the two outer come into apposition just beyond the 
median; the columnar arrangement is not so distinct as 
in Ps. congesta; at the dorsal pole there are a number of 
pits representing obsolete cirrus-sockets; some of these are 
situated directly in the interradial furrows, and their ar- 
rangement appears to be in alternating rows instead of in 
columns, suggesting the origin of the ZENOMETRINAE from 
Trichometra-like forms. 
No basal rays are visible; the radials are even with the 
edge of the centrodorsal in the median line but extend 
slightly anteriorly in the angles of the calyx where their 
tips are slightly separated; the IBr, are short, proximally 
nearly four times as broad as long in the median line but 
decreasing in width distally where they are only about 
three times as broad as long in the median line; they are 
widely separated from their neighbors; the axillaries are 
rhombic, half again as broad as long, with the anterior 
angle produced; the lateral angles extend far beyond the 
distal lateral angles of the IBr, and meet those of their 
neighbors, forming large water pores; the synarthrial 
tubercle is but slightly indicated; the first brachial is 
three times as long exteriorly as interiorly, half again as 
broad basally as the exterior length; the inner edges are 
entirely free and make approximately a right angle with 
each other; the outer sides are in apposition with the 
outer sides of the adjacent first brachials, the second brachials 
are irregularly quadrate, in contact interiorly so that a 
water pore is formed similar to that between the ossicles 
of the [Br series; the third and fourth brachials (forming 
the first syzygial pair) are together slightly longer inter- 
iorly than exteriorly, and about as broad as the exterior 
length; the next four brachials are slightly wedge-shaped, 
twice as broad as the median length, then becoming more 
obliquely wedge-shaped; as a whole the [Br series and 
Notes from the Leyden Museum, Vol. XXXIV. 
