76 Transactions.— Zoology. 
on the inner anterior angle of the inner joint of the last pair of pleopoda. 
Its function, doubtless, is to admit water to the branchial plates, and at the 
same time to prevent the ingress of sand or other extraneous matter, the 
flow of water is no doubt kept up by the movement of the branchial plates 
themselves, 
All round the outer edge of the coxz, the expanded joints of the antennz 
and the last pair of pleopoda, two distinct parallel borders are to be seen, 
the outer part of the integument being apparently produced beyond the 
inner and more opaque parts. From the inner line numerous short sete 
arise, these seldom reach much beyond the outer line. (See figs. 5 a, b, k.) 
Genus Limnoria, Leach. 
(Bate's and Westwood's British Sessile-eyed Crustacea, vol. ii., p. 849.) 
As this genus is new to New Zealand I quote here the generic characters. 
‘“ Oblong-ovate, depressed; antennzm subequal, cylindrical, not longer 
than the cephalon. Pereiopoda nearly alike, slender. Pleon six-jointed. 
Branchial plates naked. Terminal segment large, semicircular, with a 
lateral appendage on each side bearing two terminal slender styles.” 
Limnoria segnis, sp. nov. Pl. IL., fig. 1. 
Body covered with short sets. Eyes large. Neither antenna longer 
than head, inner one stouter and longer than the outer, consisting of three 
joints, of which the second is the shortest, followed by a short flagellum of 
about three joints bearing sete and long simple auditory cilia. Lower 
(outer) antennz of four joints, the third and fourth subequal and longer 
than the first and second; followed by a short flagellum of three joints 
bearing simple sete. Mandible strong, appendage small, apparently of 
only two joints, the last tipped with a few sete. Maxillipedes similar to 
those of L. lignorum, but having the plate at base much longer, narrower at 
base than towards the distal end, extremity rounded, whole margin fringed 
with short sete. Terminal segment of the tail entire rounded and flattened, 
without central dorsal carina and with the margins not raised. Last. 
pleopoda with the inner branch strong, about twice as long as broad, the 
end and outer margin supplied with sete about as long as the joint; outer 
branch small pointed at the end, and with two or three sete on the outer 
edge near the end. : 
Length—+ of an inch. 
Colour— white, opaque. 
Hab. On seaweed, Lyttelton Harbour. 
This species is very near Limnoria lignorum, the dreaded ** Gribble” 
of Europe, but it differs in several small points already mentioned. It also 
differs in habits; L. lignorum burrows into the wood of piers, piles, ete. ; 
but L. segnis I found on the roots of Macrocystis. It is very sluggish and 
