Hawaii; Renllagigedos Islands, Mexico; Panama 

 (Pacific) ; TyJosunis crocod/h/.s, Matecumbe Key, 

 Fla. ; Cuba ; Jamaica ; Trinidad ; off Venezuela ; off 

 Liberia; Gulf of Aden; Eed Sea; off Zanzibar (2 

 collections) ; off Malagasy Republic (3 collec- 

 tions) ; Farquahar Island; Comores Islands; Al- 

 dabra Island; Mauritius; Seychelles Islands; 

 Arabian Gulf; Ceylon; Madras, India; Singa- 

 pore; Gulf of Thailand; Philippines; Samoa; 

 Hawaii (2 collections) ; off west coast of Mexico 

 (2 colle^-tions) : off west coast of Panama; Cocos 

 Islaaids (eastern Pacific) ; TyJosiirus choram, Eed 

 Sea; Seychelles Islands. 



Female. — Body form as in plate 2. Specimens 

 examined had total lengths of 2.3 to 7.1 mm. (see 

 Remarks) . Greatest width in area of genital seg- 

 ment also varies but generally is not less than one- 

 fourth or more than one-third of total length. In 

 a form as variable as this, measurements of abso- 

 lute size are not a reliable taxonomic character. 

 Cephalon caligifonn, about as wide as long. Lu- 

 nules present. Thoracic segment bearing fourth 

 legs free and in the form of a neck. Genital seg- 

 ment pi'ominent, each jaosterior corner of segment 

 has a long process that may or may not extend be- 

 yond end of abdomen. Abdomen 1-segmented, 

 variable in length, and 5 to 7 times as long as wide. 

 Caudal rami (fig. 133) small, bearing six setae, 

 outermost and innermost naked, other plumose. 



First antenna 2-segmented, armed with spines 

 and setae as in figure 134. Second antenna (fig. 

 135) in fonn of a hook; terminal hook with two 

 medium setae and accessory hooklike process near 

 base. Mouthtube, mandible, and first maxilla 

 (fig. 136) of usual caligoid form; first maxilla 

 with three setae. Postoral processes present (fig. 

 136). Second maxilla of usual caligoid form, ter- 

 minating in two plumose setae. Maxilliped (fig. 

 137) in form of a stout claw, terminal claw with 

 patch of spinules and setae; patch of spinules 

 present also on penultimate segment. Furca (figs. 



138 and 139) usually spatulate but sometimes 

 rounded at tips of spines (fig. 139). Accessory 

 processes present on either side of furca and vary 

 in length. Pillai (1961, p. 114) noted differences in 

 development of these processes. Figures 138 and 



139 show two extremes in development within the 

 sample studied here — both from Tylosunts amis 

 acnis in the western Atlantic. Intermediate forms 

 were conmion. 



Legs 1 to 3 biramose. I.ieg 1 (fig. 140) exopod 

 2-segmented, first segment without spines and 

 setae, second segment with three terminal spines 

 and three inner setae; endopod 1-segmented, small, 

 bearing two small terminal spines. Leg 2 (fig. 144) 

 exopod 3-segmented, first two segments each with 

 one inner seta and one small spine on outer distal 

 corner, last segment bearing six setae and two 

 spines ; endopod 3-segmented, first segment with an 

 inner seta, second segment with two inner setae and 

 a spine on outer distal corner, terminal segment 

 bearing five setae. Leg 3 (fig. 142) exopod 2-seg- 

 mented, basal segment ^vith prominent claw on 

 outer distal comer, terminal segment bearing eight 

 short setae; endopod 2-segmented, basal segment 

 mth one inner seta, terminal segment with four 

 terminal setae. Leg 4 (fig. 143) uniramose; exopod 

 with three segments, basal two segments each with 

 short spine on outer distal comer, terminal seg- 

 ment with one long and two short spines. Leg 5 

 represented by one long process on each posterior 

 corner of genital segment. Leg 6 absent. Egg 

 strings uniseriate. 



Immature female. — Body form as in figure 144. 

 Total length 1.8 mm. Greatest width 0.82 mm. 

 Appendages as in adult except for two spines at 

 tip of leg 5 (fig. 145) . The two immature forms are 

 from Tylosurus a. acu-s from Honduras and T. 

 crococlilus from Thailand. 



Remarks. — Tlie large sample of C. laciniatus 

 studied here permits obsen-ations on size varia- 

 tion. Pillai (1961, p. 114) noted differences in 

 lengths of adult females depending on host. On the 

 basis of his collections from Indian Ocean needle- 

 fishes, he stated that those si:)ecimens from Ahlen- 

 iies Mans were distinctly larger (9.8 mm.) than 

 those from Tylosurus crocodilus (5.0 mm.). Kirti- 

 singhe (1937, p. 441) noted that his specimens of 

 this copepod from Sfrongylura leiura were larger 

 (7.5 mm.) than those from S. strongukira (5.0 

 mm.). Nuiies-Ruivo (1962b) compared the relative 

 lengths of four body divisions of seven females 

 from a single Ahlennes Mans from Angola. 



From the sample reported on here, 69 ovigerous 

 females from 65 collections representing six host 

 species were measured. Total lengths were meas- 

 ured from the anteriormost point on the cephalon 

 to the end of the 5th legs. In most specimens the 

 5th legs extend slightly beyond the caudal rami. 

 On the basis of these measurements, it is apparent 



COPEPODS AND NEEDLEFISHES 



381 



