424 
Family Thalassometridae. 
_ Pierometra venusta sp. nov. 
Fu ina noeh is thick discoidal or columnar, the ae nearly 
parallel, 6 mm broad at the base and 2,5 mm high; the cirrus ‘sockets 
are arranged in ten equally spaced ok. each column separated 
from its neighbors 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 à 
rosette of five prominent ale 
The cirriare XX—XXV, 99— 113, 77 mm long, stout basally i 
tapering slightly distally, though this distal taper is more gradual and 
therefore not so marked as in Pterometra 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 succeeding 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 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. 
The radials and division series resemble those of Pt. trichopoda 
but are slightly broader and more robust so that the arm bases open 
out at a somewhat broader angle. 
The arms are twenty-eight in number in the type. 
P, is 10 mm long with eighteen segments of which the terminal 
four or five are abruptly smaller than the preceding; it is considerably 
stouter and more sharply triangular than P, in Pt. trichopoda; P, is 
11,5 mm long with sixteen segments, strongly though not sharply trian- 
gular, 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 sixteen 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 fifteen segments, similar to P, but with 
a slightly more even taper and hence appearing stouter distally. 
Type Locality. — »Siboga« Station No. 117. 
Thalassometra marginalis sp. nov. 
This new species is closely related to Th. rustica and to Th. magni- 
cura. 
CR. - 
tnt nd es ét ue de à die 
