Cf. M. Thomson. — On the New Zealand Copepoda. 107 



Sub -family Porcellidiin^e. 

 Genus Porcellidium, Claus. 



"Body oval, depressed, in the female 6-, in the male 7-jointed. An- 

 terior antennae 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-hke 

 setae ; posterior foot-jaw 3-jointed, elongated, simple, with two small, 

 crooked, apical claws, and a laminar appendage. Outer branch of first pair 

 of feet short, 3-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 3-jointed, 

 branches subequal, except in the second pair, which has the outer 

 branch very short ; fifth pair laminar, subtriangular ; caudal segments 

 lamellar." 



1. Porcellidium fulvwn, n. sp. PL VI., figs. 10-11 ; PI. VII., figs. 8-13. 



Female.- — Body nearly a perfect oval, hardly more than half as long as 

 broad, rounded both anteriorly and posteriorly. Anterior antennae very 

 short, in length not equalling half the width of the body, 6-jointed; joints 

 diminishing in size progressively, last very small ; setae 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, falcate in outline (when seen from above), with a longitudinal crest 

 or ridge; caudal segments quadrate, ciliated at the extremity. Length 



sV incb - 



Male. — Body proportionately much broader, nearly square in front, and 

 narrowed posteriorly. Anterior antennae (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 

 setae as in female. Length J5- 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. 



