174 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



quite as long as broad; segments of P 2 only moderately spiny on the distal edge; lower 

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

 20-25 segments. 

 '. Pa 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. 



f 1 . All the cirrus segments markedly broader than long, the antepenultimate being about 

 one-third again as broad as long; P 3 similar to P 2 but slightly smaller; cirri XIV- 

 XIX, 21-25; PI 5-6 mm. long with 14 or 15 segments; P 2 9 mm. long with 17 seg- 

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

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



0-36 meters) mylitta (p. 188) 



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



than broad; P 3 is more like P or PI than PI. 



g 1 . 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; P 2 5-13 

 mm. long with 14-17 segments; P 3 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; 

 PI 8.5 mm. long with 16 segments; Pa 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 macrobrachius] 



e 2 . 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; P 2 6 mm. long; P 3 3 mm. long (Arrakan coast of Burma; ?Ceylon; 



0-24 meters) brevicirra (p. 193) 



c 2 . 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; P 3 shorter than PI. 



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

 antepenultimate; PI entirely smooth; Pj 5.5 mm. long with 14 or 15 segments; P 2 6.5 mm. 

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



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



d 2 . Cirri with not more than 20 segments of which the 4-6 preceding the penultimate bear 

 a single median dorsal spine; distal segments of P 2 with the distal ends more or less 

 spinous. 



e 1 . P 2 with 18 segments; cirri XII, 16-18, 7 mm. long; Pj 4.5 mm. long; P 2 6 mm. long; 

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



meters) studeri (p. 200) 



e 1 . P 2 with 11-13 segments. 



f 1 . Pa shorter, but not smaller and weaker, than Pj; cirri XII, 15-18; PI and P 2 with 

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



meters) informis (p. 203) 



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



7-8 mm. long; PI 3.5-4.5 mm. long with 11-13 segments; P 2 4.5-5 mm. long with 



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



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



a'. Not more than 15 cirrus segments. 



6'. Cirri with 14 or 15 segments; PI and P 2 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) 



b'. Cirri with 10-12 segments; PI and P 2 with 8 or 9 segments; P 2 half again as long as PI and P 3 , 

 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) minima (p. 196) 



