54. PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
2Caligus constrictus (not Heller).—Wilson, 1937a, p. 25, pl. 3, figs. 3a-i; 1937b 
p. 428, fig. 1—Shiino, 1959a, p. 285, figs. 9, 10. 
Hosts AND DISTRIBUTION.—7 host records: 
locality host reference 
Trivandrum, South India Caranz sansun Pillai, 1961 
Panama, Ecuador Elagatis bipinnulatus 
Caranz hippos Wilson, 1937a 
Panama Coryphaena hippurus Wilson, 1937b 
Costa Rica Seriola? species Shiino, 1959a 
Celebes Elagatis species 
Caranz species Yamaguti, 1954 
Ceylon several species of carangids Kirtisinghe, 1964 
MarrriaLt.—17 females and 1 immature male (probably late 
chalimus) (USNM 120763) from the buccal cavity of Caranxz melam- 
pygus Cuvier and Valenciennes. 
MEASUREMENTS (in mm).—16 females, 1 immature male: 
female 
mean range male 
Total length, excluding caudal setae 3. 22 2.70-3.44 2.14 
Length of cephalothorax 1. 49 1,24-1.57 1.33 
Width of cephalothorax 150 1. 338-1. 67 Aas 
Length of genital segment Lag 0.92-1.31 0.41 
Width of genital segment 0. 98 0. 83-1.08 0. 29 
Length of abdomen 0. 46 0. 31-0.56 0, 27 
Length of egg string (11 strings) 2.19 1. 57-3. 33 
Descrirtion.—Female only. Cephalothorax (fig. 22a) ovoid, con- 
sisting of cephalon and first 4 thoracic segments. Frontal region approx- 
imately one-twelfth the length of rest of cephalothorax, with median 
indentation; membrane normally projecting from leading edge of 
frontal margin in caligids much heavier in C. confusus, appearing as 
extension of frontal region. Lunules (fig. 22e) well developed, projecting 
anteriorly slightly past anteriormost portion of frontal region, project- 
ing posteriorly, on ventral surface, to junction of frontal region and 
cephalothorax. Division between frontal region and remaining areas of 
cephalothorax distinct, with saddle-like median section. Lateral surface 
of cephalothorax slightly irregular, ventral portion with fine, laterally 
projecting membrane and second, medially projecting membrane. 
Indentation present in posterior lateral cephalothoracic region of 
many caligids here present indistinctly, as slight concavity on lateral 
surface, without normally associated hairlike process or processes. 
Ficure 22.—Caligus confusus? Pillai, 1961, female: a, dorsal view; ¢, posterior cephalo- 
thoracic sinus, same view. Ventral views: b, genital segment and part of egg string; d, 
right caudal ramus; ¢, right lunule and antennule; f, oral region, showing antenna, mouth 
cone, mandible, maxillule, maxilla base (ma-2), postantennal process, and postoral process; 
g, left maxilla; 4, left maxilliped; 7, sternal furca. 
