Hawaiian Helminths, Part III 
New Opecoelid Trematodes * 1 
¥. E. Martin 2 
The opecoelid trematodes described in this 
paper were collected from Hawaiian fishes by 
the author during a sabbatical leave spent mainly 
at the Hawaii Marine Laboratory of the Uni- 
versity of Hawaii. A recent review of the family 
Opecoelidae by Skrjabin (1958) includes, 
among others, keys to the genera Opecoelus and 
Coito caecum which contain four of the five 
species described in the present paper. The fifth 
species is assigned to the genus Pseudopecoe- 
loides. A sixth species in this family, Dactylos- 
tomum caballeroi , collected in Hawaii is 
described elsewhere (Martin, in press). 
The specimens described here were fixed in 
Heidenhains’ solution, stained with either 
Mayers paracarmine or Celestin Blue B, and 
mounted in H-S-R mounting medium. 
All measurements are expressed in milli- 
meters, 
EXPLANATION OF FIGURES 
All drawings were made with the aid of a 
camera lucida. Abbreviations used: A, acetabu- 
lum; C, cecum; Ci } cirrus; CS, cirrus sac; E, ex- 
cretory vesicle; G, genital pore; M, metraterm; 
O, ovary; P, prostate; S , seminal vesicle; T, 
testis; V , viteilaria. 
1 These studies were aided by a contract between 
the Office of Naval Research, Department of the Navy, 
and the University of Southern California, NR 1 65- 
252. 
The opinions or assertions contained herein are the 
private ones of the author and are not to be construed 
as official or reflecting the views of the naval service 
at large. 
I wish to thank Drs. A. H. Banner, R. W. Hiatt, 
and L. D. Tuthill of the Marine Laboratory and the 
Department of Zoology and Entomology, University 
of Hawaii, for the use of laboratory space and equip- 
ment. 
Contribution No. 140, Hawaii Marine Laboratory, 
University of Hawaii. Manuscript received March 19, 
1959. 
"'Biology Department and Allan Hancock Founda- 
tion, University of Southern California. 
Coitocaecum Nicoll, 1915 
Coito caecum banner i n. sp. 
Figs. 1, 2 
SPECIFIC DIAGNOSIS: Based on seven speci- 
mens. Body smooth, oval, length 1.414-1.855, 
av. 1.683, greatest width 0.399-1.071, av. 0.858; 
oral sucker subterminal, length 0.21— .256, av. 
0.241, width 0.196-238, av. 0.217; acetabulum, 
length 0.308-392, av. 0.348, width 0.252-.357, 
av. 0.329; prepharynx very short; pharynx oval, 
muscular, 0.096-112, av. 0.106 long, and 0.088- 
.112, av. 0.096 wide; esophagus nearly as long 
as pharynx, glandular; ceca united near posterior 
end of body; gonads in posterior third of body, 
ovary pretesticular, smooth to weakly three- 
lobed, immediately to right of midventral line, 
0.148-224, av. 0.2 transversely, and 0.084-.126, 
av. 0.105 anteroposteriorly; seminal receptacle 
lacking; Laurer’s canal present; Mehlis gland 
diffuse, lightly staining, immediately anterior to 
ovary; proximal uterine coils contain many 
sperm, uterine coils mainly intercecal and be- 
tween ovary and acetabulum; metraterm short; 
eggs operculate, yellow, 0.048-.058, av. 0.056 
long, and 0.027— .032, av. 0.03 wide; viteilaria 
richly developed, extending from about mid- 
esophageal level to posterior end of body, usually 
separated anteriorly but joining posteriorly, in- 
vading intercecal zone; testes postovarian, tan- 
dem to oblique, smooth to indented, posterior 
testis usually larger than anterior, anterior testis 
0.231-504, av. 0.334 long, and 0.108-252, av. 
0.167 wide, posterior testis 0.175-49, av. 0.335 
long, and 0.112-291, av. 0.216 wide; seminal 
vesicle saccular, terminating shortly anterior to 
or slightly overlapping the acetabulum; cirrus 
sac short, cirrus weakly developed; genital pore 
ventral, on left side of body at postpharyngeal 
level; excretory bladder tubular, reaching to 
ovary, opening at posterior end of body. 
411 
