ENTOZOIC COPEPOD FROM JAPAN, 215 
in the form of a claw, a toothed plate, and a hook; maxille rudimentary 
and of the form common to all three genera; first maxillipede same in 
female and male, and made up of (i.) in female three parts (and not as 
Claus says four), all bearing long hooks, often bearded ; (ii.) in male, two 
parts, basal well-developed, and a terminal joint reduced to a short 
prehensile spine ; first pair of thoracic feet very different from the three 
following which are alike, and transformed into organs of adhesion ; second, 
third, and fourth thoracic somites formed of three basal parts, and of two 
rami each with three joints; fifth pair simple, two-jointed, and flat.” 
“Genus Gardella (Canu).—Body flattened, ‘ cyclopoid,’ and of distinct 
segments, male and female with ten ; first antenna seven-jointed ; second 
antenna four-jointed; mandibles large, bearing at their distal ends as 
accessory pieces a claw and two large bearded hooks; first maxillipede 
different in the two sexes and made up (1) in female of three parts carrying 
bearded hooks ; (2) in male, a basal joint carrying two bearded hooks, a 
median long and enlarged joint, toothed on its inner edge, and armed 
with two hooks on its interior surface ; finally a terminal joint in the 
form of a spine, recurved at its tip, and almost as long as the rest of the 
appendage. Thoracic feet of four first pairs of normal form, biramous 
with three joints; fifth simple, two-jointed and flat.” 
“Genus Herstliodes (Canu).—Body slightly flattened, rather elongated, 
and composed of distinct segments ; first antenna seven-jointed ; second 
antenna four-jointed ; mandibles rather large, with four accessory pieces 
(a claw, a toothed blade, two long flexible bearded sete) ; thoracic feet 
of fifth pair simple, two-jointed and flat.” 
On comparing Gordelia japonica with these descriptions, it is 
at once evident that the agreement is not sufficient to justify me 
in placing it in either of these genera, differing as it does from all 
three in many fundamental points. This may be due largely to 
its very different mode of life, for these three known genera are 
ecto-parasites, or merely commensals, whereas this creature is 
truly entozoic. It may be that its host, Hchiwrus wnicinetus, 
has anal respiration *, in which case there would be a current of 
water flowing continuously in and out of the rectum, rendermg 
the life of the parasite there far less accurately endo-parasitic 
than would be the case in the more anterior tracts of the 
alimentary canal. However, it is not at all certain that such a 
process of anal respiration takes place ; so the life of the Copepod 
may be looked upon as typically entozoic. 
According to Kossmann, Philippi, Claus, and Canu, the female 
and male of Clausidium not only differ in size, but the male is 
* See paper in the Trans. Linn. Soc. already referred to. 
