91 
which are filled up with the large disk bulging out betwen the 
arm-bases, by the syzygies which occur only sparsely, and by the 
arms branching two or three times after about I Br 20. Porphyro- 
crinus^ on the contrary, has long stem-joints, stout basal ring, close 
arm-bases, syzygies between each other joint usually, and V arms. 
Thus we have only Naiimachocrinns remaining. From this genus 
also the new type must, however, be considered to differ generically. 
The basal ring in Naumachocrinus, just as in PhrynocrinuSy is very 
short, the BB barely in contact laterally, the L. is less than the br; 
in Porphyrocrinus they are as high as broad. In Naumachocrinus 
the RR are enormously prolonged; in Porphyrocrinus, though 
slightly longer than broad and longer than the BB, only inconsider- 
ably so. In Naumachocrinus the 3 first stem-joints are short and 
discoidal then rapidly attaining the length of the full-grown joints 
(L — br at the 6th columnal); in Porphyrocrinus there are 9 short 
discoidal proximal stem-joints and the first squarish columnal is 
about the 15th stem-joint. The different appearance of the distal 
stem-joints is also very distinet; in Naumachocrinus very coarse, 
greatly swollen at the articulations, no granulation of the surface; 
in Porphyrocrinus siender, inconsiderably expanded at the ends, 
and studded with the very singular calcareous granulation v/hich 
has no correspondence among other recent Crinoids and is very 
rare also in post-permian ones. The colour in Phrynocrinus was a 
duil greenish yellow or yellowish brown, in Naumachocrinus (specimen 
in spirit) duli white in the single specimen known (no record of its colour 
in life; A. H. Clark in a letter to me); in Porphyrocrinus it is a deep 
purpie altering very slightly in spirit. By this colour it differs also 
from all the Bathycrinidæ which are whitish, greyish, or yellow. 
The diagnosis of the new genus must then be the following: 
Porphyrocrinus n. gen. 
A Phrynocrinid genus in which the stem is long and siender 
with numerous short discoidal joints proximally, long joints distally 
(L = about 2 X br). Doubtful if the granulation of the distal stem¬ 
joints can be regarded as a characteristic of generical value. BB 
about as high as broad. RR slightly higher. Arms V with low and 
flat articular Br facets. Arm-bases in close apposition. Syzygial 
articulations with 3 fossæ. (Perhaps in all Phrynocrinidæ, cf., how- 
