90 
Phrynocrinidæ. Among the genera belonging to these families we 
may immediately leave out of consideration the genera Democrinus 
and Bythocriuus as they are highly specialized types with strongly 
prolonged BB forming the chief part of the calyx. Neither Bathy- 
crinus nor Ilycrinus can be considered as being more closely related, 
as these genera have X arms and, besides this, a different distribution 
of the syzygies in proximal arm-parts. Moreover, the BB in these 
two genera are coalesced into a solid basal ring; in Porphyrocrinus 
they are separated by distinet sutures. Also Monachocrinus differs 
from Porphyrocrinus by having arms branching after the 2nd post¬ 
radial ossicle. Rhizoerinus, though with simple arms, differs by having 
the BB coalesced into a solid ring and by the radial ring being 
attached to the BB through a very close anchylosis, sometimes so 
close as to efface the sutures between the RR and the basal ring. 
Besides in Rhizoerinus the 2nd stem-joint already is squarish, in 
Porphyrocrinus the 15 th first attaining this length. In Rhizoerinus, 
as in all genera of Bathycrinidæ mentioned above, the disk is 
tolerably moderate, not stretching higher than to Br 3. In Porphyro¬ 
crinus it is, on the contrary, high and large, reaching to Br 10 or 
12. In this feature the new genus approaches Phrynocrinus which, 
as emphazised in my work Echinoderm Studies (1924, p. 213), 
has a very huge disk. In the Bathycrinidæ the Brr after Br 2 all 
seem to have high vertical flanges forming the attaching facets for 
the muscular bundles; in Porphyrocrinus the Brr are very flat and 
low, never with large ventral processes (cf. also Phrynocrinus. 
Matsum o to, Annotat. Zool. Japon. Vol. 8 p. 222 fig. f, 1913). 
The pinnulars in Porphyrocrinus are also low and never provided 
with the high flanges, protecting the genital giands, which oceur 
e. g. in Ilycrinus (cf. Echinoderm studies, fig. 125). 
From these reasons it seems most natural to range the new 
type in the Phrynocrinidæ. There are besides, as in the members of 
Phrynocrinidæ known before, no radicular appendages on the distal 
stem-joints. I will admit, however, though it does not seem prob- 
able, that they may perhaps oceur on the most distal part of the 
stem, lost when the animal was captured. Phrynocrinus is sharply 
distinguished from the new genus by the short stem-joints, by the 
low basal ring (triangular BB in P. nudus, pentagonal and slightly 
higher, L = Va br., in P. abortus), by the wide interradial interspaces 
