220 
The two dorsal vaginal pores are unarmed, 
one in each midlateral field in front of the ovary 
in the anterior part of the middle third of the 
body, well in front of the transverse vitelline 
ducts. The lateral vaginal ducts are packed with 
sperm cells and twisted in S -shaped sinuous 
ducts which run backward to unite with the 
transverse vitelline ducts near their junction 
with the median vitelline duct. 
relationships of Engrauliphila grex gen. 
et sp. nov.: 
1. Engrauliphila has a haptor-body relation 
similar to that in Engraulixenus. 
i. The stouter body is provided with a 
somewhat thicker haptoral flange and the 
clamps have more muscular and longer 
stalks. 
ii. In comparable-sized worms, the haptor is 
more extensive, reaching into the ovarian 
zone, so that the zone of pivoting is in a 
thicker region and the resulting torque 
would account for the relatively more 
massive (metahaptoral) wing. 
iii. The length of the clamp row is more than 
50% that of the relaxed worm. 
2. The inhibited clamp row retains only two 
primary clamps in all specimens. 
i. The long clamp row bears 40-48 trans- 
versely elongated stalked clamps in close 
file. 
ii. The dorsal appendix on the spring is 
stout and V-shaped. 
iii. The ventral arm of the spring is broad, 
splayed, and bifurcate. 
iv. The braces do not have bent articular 
ends. 
3. The two pairs of persistent anchors are of 
distinctive shape, both less curved than in En- 
graulixenus and entirely unlike those of Gastro- 
cotyle and Engraulicola. 
4. The penis head is devoid of forceps and 
a collar is lacking round the atrium. 
i. The corona consists of 10 sharp divergent 
spines, but no sigmoid spines. 
ii. The 15-31 testes are in 2-4 compact files, 
with 1 or 2 parovarial. 
iii. There is a vesicula seminalis in the pre- 
ovarian zone. 
PACIFIC SCIENCE, Vol. XXI, April 1967 
5. The vaginae are paired and lie in mid- 
lateral fields on the dorsal side; there is no 
median vaginal duct, since they join the trans- 
verse vitelline ducts near their confluence, as 
in Engrauliphila ; the vulvae are not supramar- 
ginal and are situated much nearer the ovary. 
i. The vulvae are less than an ovary length 
in front of the ovarian zone. 
ii. The transverse vitelline ducts are situated 
at the level of the anterior quarter of the 
ovarian zone. 
6. The pharynx is elongated ovoid, and the 
oral pouches are spheroidal and much smaller. 
i. The mean diagonal of the latter is about 
50% that of the pharynx. 
ii. The crura lack inner branches and there 
are no intercrural bridges at all. 
iii. The unequal ends of the crura are only 
slightly dilated. 
The assemblage of differences in the generic 
criteria taken together are in sufficient contrast 
to those of Engrauliphila for Engraulixenus to j 
be recognized as distinct. The specific name j 
grex refers to the exceptionally high infestation 
rate on Thris socles dussumieri. 
Engraulisco hina triaptella sp. nov. 
Figs. 18-25 
Specimens of this second species of Engrau- 
liscobina Unnithan, 1967^ were obtained from ! 
the gills of Thrissocles dussumieri (Val.) ex- | 
amined at Vizhinjom and Trivandrum on Au- 
gust 19, 1954 and October 5, 1955, respectively, j 
Two fishes examined at Vizhinjom were infected 
by four individuals (two on each fish), while 
several of the T. dussumieri examined at Tri- 
vandrum were found to be parasitized by one 
specimen of E. triaptella along with a large 
number of Engrauliphila grex. Such multiple 
infection was not observed on the several Thris- f 
socles dussumieri examined at Ayiramthengu on 
September 8, 1955, which were infected only 
by Engrauliphila grex. 
The essential asymmetry of these worms is 
shown typically in one of the longer but some- 
what contracted specimens (Fig. 18) ; a younger 
one is shown extended in Figure 19, in which 
the bulging of the shorter side is marked. The 
characteristic shape is triangular, as it is in the 
