REPORT ON THE OSTRACODA. 63 



the side, the extremities are well rounded, the posterior rather the wider of the two > 

 dorsal margin moderately arched, highest in the middle, sloping steeply in front, ventral 

 sinuated in the middle ; height equal to nearly half the length ; seen from above the 

 outline is regularly ovate, greatest width situated in the middle, and equal to rather 

 less than the height ; extremities subacuminate, and nearly equal ; end view subcircular. 

 Surface of the shell covered with minute, closely-set impressed puncta, and on the ventral 

 aspect marked with delicate longitudinal grooves. Length, l-43d of an inch (-57 mm.). 



A few specimens of this elegant species were dredged in the Straits of Magellan, lat. 

 52° 21' S., long. 68° 0' W., depth 55 fathoms (Station 313). 



I refer it, not without hesitation, to the genus Cytheve, the general configuration of 

 the shell having much in common with the Cypridse, but as in many other cases noted in 

 this memoir, the want of opportunity of examining the animal structure leaves the real 

 affinity of the species open to doubt. 



[PI. XIV. fig. 3, a-d. a Carapace seen from left side, 6 from above, c from below, 

 c^ from front. All magnified 60 diameters.] 



2. Cythere (?) laganeUa, n. sp. (PL XVI. fig. 7, a-d). 



Shell oblong, subreniform, compressed; the extremities as seen from the side are 

 boldly rounded, and nearly equal ; dorsal margin moderately arched, ventral slightly 

 sinuated ; the height, which is greatest in the middle, ecpal to more than half the length ; 

 seen from above, the outline is much compressed and widest in the middle, regularly 

 ovate, sharply-pointed in front, rather more obtuse behind; width equal to about 

 one-third of the length ; end view ovate, much higher than broad. Shell-surface perfectly 

 smooth. Length, l-58th of an inch ("44 mm.). 



Dredged in Torres Straits, lat. 11° 35' S., long. 144° 3' E., 165 fathoms (Station 185). 



[PL XVI. fig. 7, a-d. a Shell seen from left side, b from above, c from below, d from 

 front. Magnified 60 diameters.] 



3. Cythere tenera, G. S. Brady (PL XII. fig. 3, a-f). 



Cythere tenera, Brady, Monog. Recent Brit. Ostr., 1868, p. 399, pi. xxviii. figs. 29-32. 

 Cythere tenera, Brady, Crosskey, and Robertson, Monog. Post-Tertiary Entom., 1874, p. 145, pi. 

 xiii. figs. 6, 7. 



Carapace of the female oblong, compressed ; seen from the side, subcj^uadrangular, 

 rather higher in front than behind, height equal to half the length ; anterior extremity 

 rounded, posterior subtruncate, only sUghtly rounded, and smaller than the anterior ; 

 dorsal margin sloping almost in a right line from before backwards ; ventral nearly 

 straight, seen from above, compressed, sul^ovate, widest near the middle, sides neai'ly 

 parallel in the middle, and converging rather suddenly towards the extremities, which are 

 obtusely pointed, width equal to rather more than one-third of the length ; end view 



