G. M. Taomson.—On the New Zealand Entomostraca. 259 
growths as to be bright green. Eye usually red, sometimes brown or nearly 
black. Length, exclusive of caudal sete, about zy inch. Occurs all the year 
round. 
This is a very common species, occurring in every little pool, and even 
in brackish water affected by the tide. It is extremely lively in its move- 
ments, and avoids danger with much more alacrity than the majority of the 
Entomostraca, darting away on the approach of a dipping-tube or other 
large object. 
From the figure in Dana’s Atlas of Crustacea (U.S. Explor. Exped.), 
this species appears to be very near C, vitiensis, Dana. I have not seen 
any description however. 
Genus II, Arpacticus, Baird. 
Foot-jaws forming strong cheliform hands; inferior antenne simple. 
Ovary single, : 
' L, Arpacticus bairdii, nov. sp. Fig. D.8, and Fig. E.1. 
Body indistinctly ten-jointed. Cephalothorax produced downwards into 
a beak. Eye usually crimson. Superior antenns stout, composed of ten 
articulations, the last seven subequal in length, but greatly narrowing, 
earing numerous sets, which are particularly abundant on the third, 
fourth, fifth, and sixth joints ; one very long and stout seta from the fourth 
joint ; last joint terminated by about five sete of different lengths. Lower 
antennæ two-jointed; basal joint with a two-jointed, setiferous appendage ; 
ultimate joint with about nine long sets. Mandibles strong. Posterior 
foot-jaws three-jointed ; second joint ovate, with a broad, flat margin 
furnished with two rows of small teeth; third joint in form of a strong 
hook. First pair of feet with both branches three-jointed, external branch 
having the first joint short, bearing one strong seta, second much longer, 
with seta on each side, last joint very short and terminated by about five 
somewhat curved sete, the largest of them being somewhat serrated on its 
inner margin ; internal branch with first joint very long, second short, and 
third in the form of along, slender hook. Second, third, and fourth pairs of 
legs somewhat similar in shape, with the external branch in each longer 
than the internal, and all furnished with numerous set, the longer of which 
are beautifully plumose. Fifth pair with both branches formed of a single, 
nearly circular joint, bearing five sets at the extremity. All the legs more 
or less serrated on the margins. Abdomen cylindrical, tapering posteriorly ; 
posterior margins of segments minutely serrate. Bilobed extremity bearing 
on each side one seta, which exeeeds the abdomen in length, one about a 
third as long, and four short ones. Ovisae large, usually exceeding the 
abdomen in diameter, and reaching to about the penultimate segment, 
Length 4; of an inch. 
Occurs abundantly among shore-algz in Otago Harbour. 
