144 
at the base and 2.5 mm. high: the cirrus sockets are arranged in ten equally spaced columns, 
each column separated from its neighbours on either side by a shallow groove from one fourth 
to one third of a cirrus socket in width; there are two, more rarely three, cirrus sockets to a 
column ; the dorsal pole of the centrodorsal bears a rosette of five prominent tubercles. 
The cirri are XX — XXV, 99 — 113 (usually nearer the latter), 77 mm. long, stout basally 
and tapering slightly distally, though this distal taper is more gradual and therefore not so 
marked as in Pteroinetra trichopoda ; the longest cirrus segments are from one third to one 
half again as long as broad ; in the earlier segments the ventral distal edge is rather prominent ; 
after the eighth the median portion begins to project, overlapping the base of the next suc- 
ceeding segment, this after the eleventh or twelfth becoming a sharp ventral spine which 
persists as far as the twentieth, or even the twenty-third segment; at first this ventral spine 
makes a considerable angle with the longitudinal axis of the segments, but distally its outer 
part becomes more nearly parallel to it : the cirri are more broadly rounded ventrally than 
those of Pt. trichopoda, and there is no well developed sharp ridge or keel extending backward 
from the ventral spine along the midventral line of the segments; the dorsal processes arise 
very slowly, and are never very prominent ; they first appear on about the twenty-third segment ; 
the cirri are moderately compressed laterally, less so than in Pt. trichopoda. 
The radials and division series resemble those of Ptcronietra spiendida, but are slightly 
more robust. 
The arms are from 22 to 28 in number, and resemble those of Pt. sp/etidida. 
In the type (which has 28 arms) P^ is 10 mm. long with 18 segments of which the 
terminal four or five are abruptly smaller than the preceding; it is considerably stouter and 
more sharply triangular than Pj in Pt. trichopoda-.^ V., is 11.5 mm. long with 16 segments, 
strongly though not sharply triangular in section, tapering evenly to a slender tip; the outer 
segments are about twice as long as broad, without projecting distal edges; P., is 15 mm. or 
16 mm. long with 16 segments of which those in the distal half are much elongated and 
slender, with prominent spines at the prismatic angles; P^ is 17 mm. long with 15 segments, 
similar to P., but with a slightly more even taper and hence appearing stouter distally ; P. is 
17 mm. -long with 14 segments, resembling P^; Pg is 16.5 mm. long with 14 segments, resembling 
Pj; Pj is 18.5 mm. long with 16 segments, resembling P^.; P^ is slightly stouter in the basal 
portion than the preceding pinnules; on the succeeding pinnules the relative length of the stout 
basal portion increases so that the genital pinnules are broader and more sharply triangular 
than the preceding with shorter segments of which only the outermost have spines at their 
prismatic angles; the distal pinnules are about 17 mm. long, becoming gradually shorter toward 
the arm tips. 
A specimen with 22 arms about 95 mm. long is rather larger than the others, in all 
of which the arms are broken off at the base. P, is 9.5 mm. long with 14 segments; P. is 
II mm. long with 14 segments; P., is 15.5 mm. long with 17 segments; Pj is 17 mm. long 
with 15 segments; P,. is 18.5 mm. long with 17 segments; P- is 18.5 mm. long with 16 seg- 
ments; P^ is 19 mm. long with 19 segments; P,j is 19.5 mm. long with 18 segments; Pj^, is 
19 mm. long with 18 segments. 
