REPORT ON THE OSTRACODA. 145 



rounded, posterior oblique, subtruucatc, mucli compressed, so as to form a thin marginal 

 flange, and produced at the upper angle into a broad, blunt beak, obtusely angulated at 

 its junction with the ventral margin ; dorsal margin quite straight, ventral straight in 

 front, and suddenly bent upwards behind the middle ; seen from above, the outline is 

 narrow, ovate, widest in the middle, tapering to the extremities, both of which are acu- 

 minate, the posterior much attenuated ; width equal to rather more than one-third of the 

 length ; end view subovate, compressed towards the apex, and strongly mucronate in the 

 middle of the broad ventral border, width equal to two-thirds of the length. Shell 

 perfectly smooth, thin, translucent, colourless or straw-coloured, with blotches of darker 

 brown. Length, l-40th of an inch ("65 mm.). 



This species was noted in dredgings from Balfour Bay, 20 to 50 fathoms ; and 

 Christmas Harbour, 120 fathoms, both in Kerguelen Island (Station 149) ; also from oS 

 Prince Edward's Island, 50 to 150 fathoms, and from lat. 35° 39' S., long. 50° 47' W., 

 1900 fathoms (Station 323). The published figures of Pseudocy there caudata, in the 

 Monographs of Recent British Ostracoda, and of the Post-Tertiary Entomostraca have 

 been drawn from specimens higher in front, and more compressed laterally than those 

 found in the Challenger dredgings,^ so that I was at first disposed to refer the latter to a 

 diff"erent species, but a re-examination of several sets of British specimens has shown that 

 there is among them considerable variety in shape, and that the published drawings have 

 been done from rather extreme examples as regards the development of the particular 

 characters above referred to. I therefore beHeve that all, both Northern and Southern, 

 ought to be referred to one species, Pseudocythere caudata. 



[PI. I. fig. 6, a-d. a Carapace seen from left side, h from above, c from below, d 

 from front. Magnified 50 diameters.] 



2. Pseudocythere fuegiensis, n. sp. (PL I. fig. 7, a-d). 



Carapace compressed, elongated ; seen from the side, subrhomboidal, rather higher in 

 front than behind, height less than one-half of the length ; anterior extremity broadly 

 and obliquely rounded, posterior narrowed and produced in the middle into a broad 

 conical beak ; dorsal margin straight, ventral sinuated in front of the middle ; seen from 

 above, the outline is ovate, with compressed acuminate extremities, width about equal 

 to the height ; end view subcircular. Surface of the shell marked on the posterior half 

 with delicate longitudinal striae. Length, l-22d of an inch (l"l mm.). 



One specimen found in a dredging from a depth of 245 fathoms in lat. 52° 50' S., long. 

 73° 53' W. 



[PL I. fig. 7, a-d, a Carapace seen from left side, h from above, c from below, d 

 from front. Magnified 35 diameters.] 



^ Perliaps sex\ial cliaracters, or perhaps dependent on grcvrth, but of this I am not at present able to speak 

 positively. 



(ZOOL. CHALL. EXP. — PART III. — 1880.) C 19 



