197 
e- 1'., resembles P., and the succeeding [jinnules, and often 
bears a more or less developed fjonad ; all of the lower 
pinnules are invariably jjresent Ha t h v m et r i nae 
i^' Subfamil)- AiUedoninae A. H. Clark. 
Key to the Genera of the Subfamily Antedoninae. 
a' P, of the same len^^th and character as P., and the following pinnules, and 
much shorter than (usually about half as long as) P, 
b' ]Mnnule segments with unmodified, or at the most very finely spinous, 
distal edges; size medium, the arms rarely under 45 mm. in lenorth 
(Norway to the Gulf of Guinea, including the entire Medi- 
terranean basin and the east Atlantic islands; Caribbean 
Sea to Rio de Janeiro, Brazil; o — 445 Metres) Antedon 
b- pinnule segments with strongly produced, everted and coarsely spinous 
distal edges; size small, the arms never over 70 mm. and rarely over 
45 mm. in length (southern coasts of Australia northward 
through o u t the East Indian region to southern Japan; o — 275 
Metres) Compsometra 
a" P, not of the same length and character as P., and the following pinnules, 
and never only half as long as P^ 
b^ P,, of the same length and character as the following pinnules; P„ much 
longer than P.,, resembling Pj, which is still longer 
c^ Pj longer than the cirri, becoming very slender and flagellate distally, 
composed of about 40 segments (Ceylon to the Society Islands; 
o — 47 Metres) Mastigometra 
c' Pj shorter than the cirri, less slender and more or le.s.s stiffened, com- 
posed of 18 — 21 segments (Moluccas to China, end eastward 
to the Society Islands; o — -397 Metres) Euantedon 
b- P.. not of the same length and character as the following pinnules 
c' P., much the longest and stoutest pinnule on the arm 
d^ the distal ends of the cirrus segments do not overlap the bases of 
those succeeding; the dorsal edge of the outer four to si.x cirrus 
segments is about as long as the proximal border; the brachials 
have strongly produced and coarsely spinous distal edges (F" lores 
to Borneo and the Philippine Islands: o — 502 Metres) . Toxometra 
d- the cirrus segments have produced distal ends which overlap the 
proximal ends of those succeeding ; the outer cirrus segments are 
much longer than their proximal width; the branchials have smooth, 
or only very finel)- spinous, distal edges 
e^ smaller, with not over 16 cirrus segments; cirri less numerous, 
