50 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
The species name is derived from the Latin word for “like” or 
“resembling” and alludes to the similarity of P. similis to P. tenuicauda 
and P. fistulariae. 
Caligus coryphaenae Steenstrup and Liitken 
Caligus coryphaenae Steenstrup and Liitken, 1861, p. 360, pl. 4, fig. 7.—Lewis, 
1967, p. 101. figs. 37-39. 
Hosts AND DISTRIBUTION.—See Lewis (1967). 
MareriaL.—4 females and 2 males from the external surface of 
Euthynnus yaito (Jordon and Evermann); 4 females and 1 male from 
the external surface of Sarda orientalis (Schlegel); 1 male from the 
external surface of Grammatorcynus bilineatus (Riippell); 2 females 
from the external surface of Caranz melampygus? Cuvier and Valen- 
ciennes; 7 females and 1 male from the external surface of Katsuwonus 
pelamis (Linnaeus). (All specimens retained by author.) 
MBASUREMENT (in mm).—15 females, 5 males: 
females males 
mean range mean range 
Total length, excluding caudal 
setae 4, 76 4,51-6.36 3.99 3. 55-4, 77 
Length of cephalothorax 241 2. 48-3. 33 2.60 2. 37-3. 00 
Width of cephalothorax 2. 28 2.04-2.96 1.97 1. 81-2. 37 
Length of genital segment eS 0. 96-1.33 0. 64 0. 59-0. 85 
Width of genital segment 1, 25 1,11-1.52 0, 86 0. 78-1. 07 
Length of abdomen 0. 90 0. 70-1.33 0.61 0. 52-0. 74 
Length of egg strings (13 strings) 4, 67 4, 22-5. 70 
DerscripTion.—sSee Lewis (1967). 
Remarks.—tThe size of the Eniwetok specimens is less than that of 
the specimens described from Hawaii. The reasons for this difference 
warrant further study. One possible source for the reasons may be 
that the specimens were all taken from fishes captured in the atoll 
lagoon; no host specimens were available from the open ocean outside 
the lagoon. 
Caligus productus Dana 
Caligus productus Dana, 1853, p. 1354, pl. 94 (fig. 4).—Lewis, 1967, p. 116, figs. 
43-45. 
Hosts AND DISTRIBUTION.—See Lewis (1967). 
Marterriat.—2 females (USNM 120759) from the gill cavity of 
Sarda orientalis (Schlegel); 1 female and 2 males from the gill cavity 
and buccal cavity of S. orientalis; 5 females and 2 males from the gill 
cavity and buccal cavity of S. orientalis. 
