OSTRACODA COLLECTED IN THE SOUTH SEA ISLANDS. 501 



Habitat. — Noumea, in shore-sand from near Artillery Point ; also dredged in 2-6 

 fathoms. 



Cy there Packardi, G. S. Brady (PI. II. fig. 19). 



Cy there Packardi, Brady, " Ostracoda of Challenger Expedition," p. 88, pi. xix. fig. 2 a-d. 



The types of this species were found sparingly in a " Challenger" dredging from off 

 Booby Island. 



There are two distinct forms of shell, probably belonging respectively to the two 

 sexes. One of these is well figured in the "Challenger" Report. This I believe to be the 

 female; the other is figured in this paper. It differs from the "Challenger" form in 

 being less tumid, and in having a much more pronounced production of the shell at the 

 postero-ventral angle. The surface is marked with very prominent longitudinal ribs, which 

 in the female are indicated only faintly, or not at all. The male is smaller, and has the 

 hinge-tubercle much more strongly marked than in the opposite sex. 



Habitat. — Noumea, in shore-sand from Porcheron's Beach and Artillery Point, also 

 dredged in 2-6 fathoms ; Suva, mud-flats between tide-marks ; Levuka and Vuna Point, 

 Taviuni, between tide-marks; Sava-Sava Bay, 4 fathoms; Rambe Island, between tide- 

 marks ; Loma-Loma, in shore-sand; Lufi-Lufi and Apia, Upolu, in shore-pools. 



Cythere deltoides, n. sp. (PL II. figs. 17, 18). 



Shell, seen from the side, oblong, quadrangular, highest in front, height equal to 

 rather more than half the length. Anterior extremity wide and moderately rounded, 

 posterior much narrower, sharply produced below the middle into an angulated and 

 irregularly dentated promontory, above which it slopes steeply backwards, the middle of 

 the slope broken by a sharp angular projection; dorsal margin gibbous in front, thence 

 sloping backwards in a sinuous curve, and terminating in a sharp angle ; ventral margin 

 straight or more or less irregularly sinuated. Seen from above, the outline is irregular — 

 doubly triangular — a large anterior triangle whose base forms the widest part, and a 

 much smaller posterior triangle applied by its base to the larger ; anterior extremity 

 rectangularly truncated ; the lateral margins diverging strongly and very irregularly to 

 the base of the larger triangle, where they suddenly dip inwards at a right angle, running 

 with a wide, much dentated sweep to the posterior extremity, which is narrower than the 

 anterior and emarginate in the middle. Surface of the shell marked with numerous 

 subcircular pittings, hinge-tubercle conspicuous, a more or less distinct ridge running 

 obliquely across the valve from near the middle of the anterior margin to the posterior 

 dorsal angle, the anterior portion of the valve ending precipitously in a transverse ridge 

 at the posterior fourth. Length '66 mm. 



Habitat. — Port of Noumea, in shore-sand and near Artillery Point, and dredged in 

 2-6 fathoms ; Lufi-Lufi, Upolu, reef and shore-pools ; Apia, Upolu, reef and shore-pools. 



