EEPOllT ON THE OSTRACODA. 161 



conspicuous lateral prominences and several lesser humps and sinuations. Surface of the 

 shell sculptured with numerous large, deep and closely-set angular cavities ; the centre of 

 the valves elevated ; running nearly parallel with the dorsal and ventral margins, but 

 considerably inside of these are two rounded but very prominent and thick ridges, 

 separated from each other, however, by a distinct interval at the extremities. Length, 

 ^th of an inch (5 '2 mm.). 



This very fine species, of which one specimen only was obtained, was dredged in a 

 depth of 38 fathoms, off the entrance to Port Philip, South Australia, on a sandy bottom 

 (Station 161). In order to preserve entii'e so interesting a specimen, the animal has not 

 been submitted to dissection, but the general appearance of the species recalls so vividly 

 that of Philomedes folini (described by me in the Zoological Proceedings, loc. cit.) that I 

 cannot hesitate to refer it to the same genus. I have much pleasure in dedicating it, as 

 being perhaps the finest of the Ostracoda taken during the Challenger Expedition, to my 

 friend Professor Sir C. Wyville Thomson. 



[PI. XXXVI. fig. 1, a-c. a Carapace seen from the left side, h from below, c from 

 front. An magnified 14 diameters.] 



Asterope, Philippi. 



One or two specimens, in an imperfect condition, but probably belonging to this genus 

 were found in a dredging from Station 33, off Bermudas, in a depth of 435 fathoms. 



Family II. Conchoeciad.^. 



Sub-family Halocyprinse, Dana. 



Shell very thin and flexible, usually neither calcareous nor horny, but almost mem- 

 branaceous ; more or less distinctly notched and emarginate on the anterior surface (as 

 in the Cypridinidse) for the protrusion of the posterior antennae. Eyes wanting. 

 Anterior antennse in the female small, indistinctly jointed, and bearing near the apex a 

 brush of ciliated auditory setae ; in the male, much larger and distinctly jointed ; between 

 the antennae a long tentacle directed forwards, and bearing at the apex a club-shaped 

 dilatation. Posterior antennte almost like those of CypricUna ; basal portion large and 

 stout ; natatory branch beset with long, plumose setae, and having a smaller secondary 

 appendage, which in the male is prehensile. Mandibles distinct, toothed at the apex, 

 provided with a large pediform, four-jointed palp, the basal joint of which is very large, 

 extending downwards as far as the apex of the mandible, and, like it, armed with 

 numerous terminal teeth ; last three joints slender, and bearing numerous setae. Two 

 pairs of pediform maxiUae, the first ^ composed of three lobes, of which the two basal 



^ Dana appears to consider this as forming two distinct maxillse, the two basal lobes constituting the tirst, the two 

 last the second maxilla. 



(ZOOL. CHALL. EXP. — PART HI. 1880.) C 21 



