'47 
decrease in height and resolve themselves intu a sliarp carinate 
process crowned with spinules ; P,, tliouoh longer and stouter 
than the following, is slender and evenly tapering, composed of 
segments which beyond the second arc much longer than broad, 
more or less constricted centrally, with produced and spinous distal 
edges (Yucatan to Grenada, West Indies) Stylometra 
c- less than 15 (10 — 13, usually 10) arms; division series usually 2, 
sometimes 4 (3 + 4) ; P, very stout, much stouter than the succeeding 
pinnules, though with a delicate tip (Morocco and Madeira 
s o u t h w a r (.1 to Ascension and the C r o z e t Islands; east 
Africa to the Kermadec, Galapagos, Hawaiian a n el 
western Aleutian Islands, and southern Japan). . . Thalassometra 
ossicles of the division series, and of the arm bases smooth, without 
spines on the dorsal surface, though they may have irregular processes 
on' their lateral borders; Pj, though larger and stouter than those suc- 
ceeding, is not especially enlarged 
c' not more than 1 5 arms 
d' cirri with more than 50 segments, very long and very slender ; arms 
slender, very narrow, strongly compressed laterally; a prominent 
narrow median keel on the ossicles of the division series, which 
is continued the entire length of the arms; 10 — 12 arms; division 
series 2 ; proximal cirrus segments with a distinct keel in the mid- 
dorsal line, and usually with a small spine in the middle of the 
distal dorsal edge (Queensland and Timor to the Philip- 
pine Islands; southern Japan) Daidalometra 
d" cirri with less than 35 segments 
e^ cirri with 30 — 34 segments, of moderate length and moderately 
slender ; ossicles of the division series broad, very slightly 
convex dorsally but with a prominent sharp median carinate 
process, everywhere in close lateral apposition ; lateral portion 
of the distal borders of the I Br,, 1 1 Br, and the first brachial 
produced, forming rounded tiiin anterior processes which im- 
bricate over the bases of the succeeding ossicles; brachials 
with a very faint and obscure median carination ; 13 — 15 arms; 
division series 2 (sou t h west er n Japa n) Lissometra 
e- cirri with at most 27 (usually between 20 and 25) segments, short 
and stout; division series and arm bases well rounded dorsally, 
appearing narrow and only slightly flattened against their 
neighbours; 10 — 20 arms; division series 2 (Kei Islands 
to southern Japan and the Hawaiian Islands) . Parametra 
C" more than 1 5 (usually 20) arms 
