158 
Parametra A. H. Clark. 
Key to the Species of the Genus Parametra. 
a' Arms evenly rounded dorsally, the brachials, including the distal, entirely without 
a median elevation or carination, and with only very slightly produced edges; 
elements of the division series very strongly convex dorsally, entirely without 
swollen or everted borders, their centres occupied by a very broad, low and 
obscure median swelling (H a waiian I slands ; 345 — 634 Metres) .... fishcri 
a^ Brachials always with the mid-dorsal portion abruptly raised, forming a more or 
less evident carinate process; borders of the ossicles of the division series, which 
are only slightly convex dorsally, more or less raised or everted ; a more or 
less developed notch is present between the outer portion of te proximal borders 
of the axillaries and second brachials and the preceding ossibles, these notches, 
when the arms are in apposition, forming pores through which water reaches 
the sides of the disk 
b^ the ossicles of the division series and the earlier brachials have strongly everted 
edges; the distal, or both, elements of the division series and the first brachial 
pair have a rounded and inconspicuous carinate process; the cirri have about 
20 segments (Kei and Lesser Sunda Islands; 216 — 252 Metres) . . compi'essa 
b- the ossicles of the division series and the earlier brachials have moderately 
everted distal edges; the ossicles of the division series and the first two 
brachials are either smooth dorsally, or bear rounded and inconspicious carinate 
processes; more than 20 cirrus segments 
c^ from 10 to 18 (but very rarely more than 15) arms; ossicles of the division 
series usually entirely without median carination; sides of the division series 
usually quite smooth, buth the lateral borders of the ossicles of the IBr 
series may be crenulate, or more or less tubercular (Hong Kong and 
Formosa to southern Japan; 128 — 306 Metres) orion 
c" from 16 to 20 (usually from 17 to 20) arms; ossicles of the division series 
usually with a low and narrow median carination : sides of the division 
series usually with a more or less developed tubercular ornamentation 
(Philippine Islands; 148 — 502 Metres) granulata 
1. Parametra fisheri {K. H. Clark). 
A. H. Clark. Proc. U.S. National Museum, vol. 34, 190S, p. 223 (Thalassometra fislieri). 
2. Parametra compressa (P. H. Carpenter). 
P. H. Carpenter. "Challenger" Reports. Comatulae, 1888, p. 222, pi. 4I; [Antedon com- 
pressa, part). 
A. H. Cl.'VRK. Smithsonian Miscellaneous Collections, vol. 61, 19 13, N" 15, p. 45 (Parametra 
compressa). 
