Hawaiian Helminths 1. Trigonocryptus 
conus n, gen. ? n. sp. (Trematoda: Fellodistomidae) 1 
W. E. Martin 2 
This work was done at the Hawaii Marine 
Laboratory, University of Hawaii. Twenty- 
nine balloon fish, Tetraodon hispidus L., col- 
lected by trap, were examined for helminths. 
Four harbored in their intestine a total of eight 
trematodes which do not fit into any genus or 
species thus far described. 
The worms were killed in cold Heidenhain 
fixative under light cover glass pressure, 
stained in celestine blue B, and mounted in 
H.S.R. Microscopic Mounting Medium. 
All measurements are expressed in 
millimeters. 
Trigonocryptus n. gen. 
GENERIC DIAGNOSIS: Fellodistomidae: Small 
conical trematodes with ventrolateral body 
folds separated posteriorly and converging 
anteriorly. Posterior end of body bears a short 
velum laterally and dorsally. Inverted tail cone 
present. Cuticula relatively thick, spined. Oral 
sucker subterminal with ventrolateral exten- 
sions. Ventral sucker large, transversely elon- 
gate and ridged, indented anteriorly and pos- 
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 165-252. 
The opinions and assertions contained herein are the 
private ones of the author and are not to be construed 
as official or reflecting the views of the Navy Depart- 
ment or the naval service at large. 
1 wish to express my appreciation to Drs. A. H. 
Banner, R. W. Hiatt, and L. D. Tuthill of the Hawaii 
Marine Laboratory and the Department of Zoology and 
Entomology, University of Hawaii, for the use of space 
and equipment during my sabbatical leave. 
Contribution No. 107 Hawaii Marine Laboratory, 
University of Hawaii, Honolulu. Manuscript received 
March 4, 1957. 
2 University of Southern California, Los Angeles, 
California. 
teriorly. Prepharynx and esophagus very short. 
Pharynx oval to spherical. Ceca short, sac- 
cular, not extending posterior to mid-body. 
Testes paired, opposed, oval, near posterior 
end of body. Cirrus sac oval to nearly spheri- 
cal, immediately anterior to or slightly over- 
lapped by acetabulum, encloses a weakly 
bipartite seminal vesicle, a well-developed 
prostate and a short cirrus. Ovary oval, med- 
ian, partly between to a short distance anterior 
to testes. Seminal receptacle near, usually 
smaller than, ovary. Mehlis gland beside 
ovary, inconspicuous. Vitelline follicles in two 
major groups on each side of body extending 
from anterior acetabular to posterior oral 
sucker levels. Uterus mainly confined to pos- 
terior half of body, between and anterior to 
testes. Uterus and cirrus use common genital 
atrium which opens to outside medially and 
ventral to gut bifurcation. Eggs oval, nu- 
merous, operculated, with tiny knob at ano- 
percular end. Excretory bladder U-shaped. 
Parasitic in the intestines of marine fish. 
genotype : Trigonocryptus conus. 
Trigonocryptus conus n. sp. 
Figs. 1-5 
specific diagnosis: With characters of 
genus. Body conical and pink in life, triangu- 
lar when fixed under pressure. Cuticle 0.012- 
0.016 thick, armed with spines. Spines approx- 
imately 0.017 long with shouldered peripheral 
terminations (Fig. 4). Body 1.37-1.82, average 
1.58 long and 0.98-1.4, average 1.24 wide. 
Oral sucker subterminal, muscular, with folds 
meeting those of the body wall, 0.39-0.55, 
251 
