Thomson. — Ou Ncio Zealand Crustacea. 263 



to time along with other pelagic South Pacific and antarctic 

 species. 



Hi/perla diibia, n. sp. 



A new hyperid, not referable to any described species, was 

 picked up by my wife on the Ocean Beach, Dunedin. It was 

 a female, carrying a large number of ova. Pending the pub- 

 lication of the "Challenger" report on the Amphii^hoda, I 

 have provisionally named this species H. diibia. 



Sub-order. Isopoda. 



90. Ceratothoa lineata, Miers. 



A single specimen of this species (which was previously 

 unknown to me) was forwarded by Dr. Gaze, of Westport, 

 who took it from the mouth of a guard- (gar- ?) fish at Nelson. 



94. Nerocila vicccleayil, Leach. 



Two specimens of this species (also previously unknown to 

 me) were forwarded by the same correspondent, who informs 

 me that they are common on kahawai {Aryi2)is salar) and 

 other large fishes on the west coast of this island. 



Genus Cassidina. 



In the absence of a copy of Dana's "U.S. Explor. Expedi- 

 tion," the following generic characters are taken from Milne- 

 Edwards's " Histoire Naturelle des Crustaces," vol. iii., 

 p. 223 :— 



Head large and very short, almost semi-lunar, deeply sunk 

 into the thorax, produced anteriorly into a median process 

 which is directed obliquely downwards between the bases of 

 the antennae. Eyes oval in form, occupying the lateral angles 

 of the head. Antennae and mouth-apparatus as in Sphceroma. 

 Thoracic segments very large and prolonged on each side in 

 the form of a thin plate, which is produced obliquely down- 

 wards and ends in an almost straight margin. The first seg- 

 ment of the thorax is produced forwards on each side of the 

 head almost to the bases of the antennae. Abdomen as wide 

 as the thorax in front, but narrowing rapidly ; it is divisible 

 into two portions, the anterior of which is formed of several 

 segments anchylosed in the median line, but separate at the 

 sides, and tlie posterior scutiform portion. The ambulatory 

 feet are slender and bi-imguiculate. The first five pairs of 

 abdominal appendages are similar to those of SphcEvoiiia, but 

 have the margin of the external terminal lamella much more 

 setose. The last pair of abdominal feet also resemble those 

 of Spharoma, only their terminal movable lamella is almost 

 rudimentary, while the prolongation of the basal articulation 



