174 BULLETIN 8 2, UNITED STATES NATIONAL MUSEUM 



quite as long as broad; segments of Pj only moderately spiny on the distal edge; lower 

 pinnules, except for Pj and sometimes Pj, not unusually stiff; cirri 10-12 mm. long with 

 20-25 segments. 

 e'. Pj with 16 or 17 segments and from half again to twice as long as Pi, which has 13-15 

 segments; arms 55-110 mm. long. 

 /'. All the cirrus segments markedly broader than long, the antepenultimate being about 

 one-third again as broad as long; P3 similar to P2 but slightly smaller; cirri XIV- 

 XIX, 21-25; Pi 5-6 mm. long with 14 or 15 segments; Pj 9 mm. long with 17 seg- 

 ments; Pa 6-6.5 mm. long with 14 segments; P4 5 mm. long with 12 or 13 segments; 

 arms 55-75 mm. long (Philippine Islands and Hong Kong to Singapore; 7Borneo; 



0-36 meters) mylitta (p. 188) 



p. The two to six cirrus segments before the penultimate are scarcely, if at all, longer 



than broad; P3 is more like P* or Pi than P2. 



ff'. The 5 or 6 cirrus segments preceding the penultimate are almost or quite as long 



as broad; cirri XII-XX, 20-23, 10 mm. long; P, with 13 or 14 segments; Pj 5-13 



mm. long with 14-17 segments; P3 very similar to Pi with 15 segments; arms 



65 mm. long (Kurrachi to the Maldive Islands; littoral) mollis (p. 191) 



{g^. The 2 or 3 cirrus segments preceding the penultimate are almost or quite as long 

 as broad; cirri XV, 21-22, about 12 mm. long; Pi 5.5 mm. long with 14 segments; 

 P2 8.5 mm. long with 16 segments; P3 5.5 mm. long with 12 .segments; the very 

 slender arms are up to 110 mm. long (from the Philippines to the Kei Islands 



and Amboina; 0-50 meters) Oligometra serripinna raacrobrachius] 



e'. Pj with 12 or 13 segments, not much longer than Pi, which has the same number of seg- 

 ments; arms about 35 mm. long; cirri XIV, 21-23 (usually the latter), 8 mm. long; 

 Pi 4.5 mm. long; P2 6 mm. long; P3 3 mm. long (Arrakan coast of Burma; ?Ceylon; 



0-24 meters) brevicirra (p. 193) 



c'. Earlier cirrus segments dorsally with a transverse ridge which may persist until the end of 



the cirrus, or may transform into a single median tubercle or short spine on a few of the 



segments preceding the penultimate; P3 shorter than P|. 



d'. Cirri with 18-23 segments which bear a transverse ridge as far as, and including, the 



antepenultimate; P2 entirely smooth; Pi 5.5 mm. long with 14 or 15 segments; P2 6.5 mm. 



long with 17 segments; P3 4.5 mm. long with 14 segments; arms about 50 mm. long 



(Saleyer; ?Hong Kong; littoral) laevipinna (p. 197) 



(P. Cirri with not more than 20 segments of which the 4—6 preceding the penultimate bear 



a single median dorsal spine; distal segments of P2 with the distal ends more or less 



spinous. 



e'. P2 with 18 segments; cirri XII, 16-18, 7 mm. long; Pi 4.5 mm. long; P2 6 mm. long; 



P3 3 mm. long; arms 45 mm. long (Dirk Hartog Island, Western Australia; 13 



meters) studeri (p. 200) 



e'. P2 with 11-13 segments. 

 /'. P3 shorter, but not smaller and weaker, than Pi; cirri XII, 15-18; Pi and P2 with 

 11 or 12 segments; arms about 40 mm. long (Philippine Islands to Singapore; 0-42 



meters) informis (p. 203) 



p. Pj much smaller and weaker, and much less stiff, than P,; cirri XIV-XVI, 14-20, 

 7-8 mm. long; Pi 3.5-4.5 mm. long with 11-13 segments; P2 4.5-5 mm. long with 

 11 or 13 segments;P3 3 mm. long with 10-12 segments; arms 35-50 mm. long (Baga- 

 moyo and Mauritius to tlie Maldive Islands; ?Ceylon; littoral), modica (p. 205) 

 a'. Not more than 15 cirrus segments. 

 6'. Cirri with 14 or 15 segments; Pi and P2 with 11 segments of which the seventh and following 

 are about twice as long as broad; arms 40-45 mm. long (from southwestern Japan south- 

 ward to the Kei Islands and westward to the Java Sea; 9-90 meters) parva (p. 195) 



V>. Cirri with 10-12 segments; Pi and P2 with 8 or 9 segments; Pj half again as long as P, and Pj, 

 stiff and spinelike, the outer segments about three times as long as broad with long and 

 prominent spires at the prismatic angles; arms 35-40 mm. long (from the Philippine Islands 

 to Celebes, the Borneo Bank, the Kei Islands, and Salomakiee [Damar] Island; 33-90 

 meters) iiunima (p. 196) 



