G. M. Tuomson.—On the New Zealand Copepoda. 107 
Sub-family PorcELLDINÆ. 
Genus Porcellidium, Claus. 
“ Body oval, depressed, in the female 6-, in the male 7-jointed. An- 
terior antenne 6-jointed, in the male obtuse, knotted, and adapted for 
clasping ; posterior 4-jointed, secondary branch of moderate size, 1-jointed, 
attached to apex of second joint. Mandibular-palp large, forming an 
irregularly-shaped oblong lamina, beset with numerous stout ciliated 
filaments. Maxilla composed of a toothed masticatory branch, with a 
complex 4-digitate palp. Anterior foot-jaw not forming a prehensile hand, 
divided at the apex into short digits, which bear slender, terminal, claw-like 
sete; posterior foot-jaw 8-jointed, elongated, simple, with two small, 
crooked, apical claws, and a laminar appendage. Outer branch of first pair 
of feet short, 9-jointed; inner branch composed of one excessively broad 
triangular joint, which is clawed at the apex, claws bearing delicate laminar 
expansions. Second third and fourth pairs with both branches 8-jointed, 
branches subequal, except in the second pair, which has the outer 
branch very short; fifth pair laminar, subtriangular ; caudal segments 
lamellar.” 
1. Porcellidiwn fulvum, n. sp. Pl. VI., figs. 10-11; Pl. VII., figs. 8-18. 
Female.—Body nearly a perfect oval, hardly more than half as long as 
broad, rounded both anteriorly aud posteriorly. Anterior antenne very 
short, in length not equalling half the width of the body, 6-jointed; joints 
diminishing in size progressively, last very small; setæ numerous. Feet 
of first pair with the inner branch forming an elongated triangle, the 
. terminal claws long and straight. Fifth pair of feet subtriangular, acute at 
apex, faicate in outline (when seen from above), with a longitudinal crest 
or ridge; caudal segments quadrate, ciliated at the extremity. Length 
gy inch. 
Male.—Body proportionately much broader, nearly square in front, and 
narrowed posteriorly. Anterior antenne (apparently 6-jointed) greatly 
swollen and knotted. Fifth pair of feet subquadrate, curved, widely ex- 
panded at the extremity and fringed with (about 6) sharp spines ; caudal 
sete as in female. Length gj inch. 
The two sexes are so different in general form that they might almost be 
taken at first for distinct species; the specimens however from which the 
figures were taken were in the act of copulation when captured. One of the 
most singular points of difference is their size, the females being in almost 
all cases half as large again as the males. The integument in this species 
is thickly marked with circular depressions or pits. : 
The colour is most commonly a uniform clear yellow, but is sometimes 
nearly transparent, or banded with red. 
