Leg 5 (fig. 11) a small knob bearing two naked 

 setae. Leg 6 absent. 



Egg sacs about 400 /x long, containing 28 to 32 

 eggs. 



Color in life unknown ; preserved material with 

 purplish opaque spots scattered along middorsal 

 line of body. 



Male. — Unknown. 



Etymology. — The specific name argulus refers 

 to the resemblance of the cephalon to the bran- 

 chiuran genus Arguhis. 



Remarks. — This species may be separated from 

 other species of the genus with spinules on the 

 intercoxal plates by a combination of the shape 

 of the cephalon, shape of the e.gg sacs, and the rows 

 of broad spinules on the genital and abdominal 

 segments. 



Ergasilus coleus Cressey, New Species 



Figures 17 to 25 



Specimens studied. — A single collection contain- 

 ing 4 females from Sfrongyhira urviUii from the 

 Philippines ; three collections from S. strongylura, 

 one with 4 females from Cagayan de Misamis, Min- 

 danao, Philippines, one with 6 females from 

 Sandakan Bay, Borneo, and one with 16 females 

 from Porto Novo, Madras, India; two collections 

 from Xenentodon cancila., one from USNM 

 149701 containing the holotype female (USNM 

 125679) and 10 paratype females (USNM 125680) 

 from Travancore, India, and the other from SU 

 34948 with 40 females from Calcutta, India. 



Feviaie. — Body form as in figure 17. Total 

 length 530 /x. Greatest width 210 /*. Cephalon sub- 

 divided ; anterior portion bearing first and second 

 antennae, posterior portion bearing moutli parts 

 and first two thoracic legs. Tlioracic segments 

 bearing legs 3, 4, and 5 free. Genital segment (fig. 

 18) about twice as long as wide with thin wrinkled 

 surface inconspicuously sclerotized. Abdomen 2- 

 segmented; sclerotization heavier than in genital 

 segment; articulation between segments obscure. 

 Caudal rami small, nearly square, inner posterior 

 corners produced to form stout spinelike processes; 

 each ramus bearing three setae as indicated in 

 figure. 



First antenna (fig. 19) 6-segmented, armed as in 

 figure. Second antenna (fig. 20) 4-segmented; 

 first three segments enclosed in hyaline wrinkled 

 sheath; claw of antenna free of sheath but pierc- 

 ing sheath of opposite second antenna as the two 



appendages encircle gill filament of host (sheath 

 may provide soft surface for claw of opposite 

 member to penetrate to secure copepod to host's 

 gill). Mandible, first maxilla, and second maxilla 

 (fig. 21) very small; mandible and second max- 

 illa easily seen under oil immersion, but first 

 maxilla reduced to a very small knob between these 

 two and bearing a single short seta. Maxilliped 

 absent. 



Legs 1 to 4 biramose. Leg 1 (fig. 22) rami 3- 

 segmented, outer distal spine on corner of exopod 

 first segment very small. Leg 2 (fig. 23) rami 3- 

 segmented; devoid of spines, setae arranged as 

 in figure. Leg 3 (fig. 24) rami 3-segmented; devoid 

 of spines as in leg 2, bearing one additional seta on 

 exopod last segment; outer seta on endopod last 

 segment short. Leg 4 (fig. 25) exopod 2-segmented ; 

 endopod 3-segmented; rami armed as in figure. 

 Spine and seta formulas for legs 1 to 4 follow: 



Leg 5 (see fig. 18) a free segment with two ter- 

 minal setae and one seta near base (a subterminal 

 seta could not be found). Segment bearing leg 5 

 fused with genital segment. Leg 6 absent. 



Egg sac 480 /x long, bearing about 40 eggs. 



Color in life unlvnown. 



Mal^. — Unknown. 



Etymology. — The specific name colons is Latin 

 for "sheath" and refers to the nature of the sec- 

 ond antenna. 



Remarks. — Tiiis species may be separated from 

 all known species of Ergci.'iihis, except E. amplec- 

 tens Dogiel and Akhterov (1952) by the presence 

 of the sheath surrounding the second antenna. It 

 differs from amplectens by the nature of the gen- 

 ital segment; in amplectens the genital segment 

 and abdomen are well defined, whereas in coleit.s 

 the genital segment appears to be encased in a 

 sheath similar to that on the second antenna. 



Ergasilus semicoleus Cressey, New Species 



Figures 26 to 32 



Speci7nens studied. — A single collection from the 

 gill filaments (mostly in upper branchial area — 

 between demibranchs of 4th gill arch) of six 

 Strongylura kreiftii (USNM 173999) from a large 



COPEPODS AND NEEDLEFISHES 



353 



