446 Mr. G. M. Thomson on two new 
Dorsum with three rows of tubercles, the posterior two rows 
very faint. eels with lateral margins entire, though 
granular, those that bear the pore notched or emarginate 
posteriorly. Pores completely marginal, though just visible 
when the segment is viewed from above. 
Caudal process semicircularly rounded. 
Anal sternite bitubercular. 
Sterna not spined. 
Polydesmorhachis atratus, sp. n. 
? .—Colour of upper surface a uniform blackish brown, 
the edges of the keels only indistinctly yellow; legs and 
antennee infuscate ; sterna pale. 
Antenne short, their length a little less than width of 
second segment. 
First tergite mesially depressed, elevated laterally and 
posteriorly, beset with tubercles and granules. Keels of 
segments 2 to 7 elevated, the rest horizontal; anterior and 
posterior borders of keels as far back as the seventeenth 
segment directed obliquely forwards, almost smooth, anterior 
border basally shouldered, anterior angle rounded and. nearly 
rectangular, strongly convex on the sixteenth, seventeenth, 
and eighteenth segments; anterior border straight on the 
anterior part of the body, convex on the posterior seven keel- 
bearing segments; posterior angle never spiniform, obtusely 
rounded, square on the sixteenth, produced on the seventeenth 
to nineteenth. ‘The dorsal surface of keels and of the rest of 
the segment granular, in addition to the tubercles ; the suture 
of the segments costulate. 
Measurements in millimetres.—Total length 61; width of 
second segment 8°5, of fifth 8-5. 
Loc. Palawan Island, between Borneo and the Philippines 
(A. Hverett). 
LI.—On two new Gammarids from New Zealand. 
By GrorGE M. 'THomson, F.L.S. 
[Plate X.] 
Tue Amphipods described in the present paper were 
obtained in the Bay of Islands in January 1884. ‘They were 
taken by me in the dredge in about 8 fathoms of water on a 
nearly clean sandy bottom. Only males were met with, and 
as, in the case of both species, they were very distinct and 
conspicuous on account of the abnormal development of the 
