REPORT ON THE OSTRACODA. 79 



middle. Surface of the valves profusely marked with rounded, impressed puncta ; hinge- 

 tubercles conspicuous ; margins produced, especially at the two ends of the shell, so as to 

 form a squamous encircling fillet, which in front and behind is marked liy small marginal 

 teeth and numerous transverse hair-like lines ; along the contact margins of the valves, 

 both on the dorsal and ventral surface, is a distinct angular depression. Length, l-25th 

 of an inch ('l mm.). 



Dredged plentifully in Balfour Bay, 20 to 50 fathoms, and Eoyal Sound, Kerguelen 

 Island, 28 fathoms ; off" Prince Edward's Island, 50 to 150 fathoms ; off East Moucoeur 

 Island, Bass' Strait, 38 to 40 fathoms ; and Port Jackson, Australia, 2 to 10 fathoms. 

 Seen on the dorsal surface, this species bears a close resemblance to the common British 

 Cythere alhonKiculata, Baird, but the shell is much more coarsely sculptured, while the 

 spinous margins, and very broadly reniform lateral outline are constant distinctive 

 characters. 



[PL XX. fig. 1, a-f. a Carapace of female seen from left side, h from above, c 

 from below, d from front, e male seen from left side, / from above. AH magnified 40 

 diameters.] 



31. Cythere sjxyeri, G. S. Brady (PI. XX. fig. 2, a-f). 



Cythere speyeri, Brady, Ann. and Mag. Nat. Hist., 1868, ser. 4, vol. ii. p. 222, pi. xv. figs. 8-11. 

 Cythere speyeri, Les Fonds de la Mer, torn. i. p. 99, pL xii. figs. 8-10. 



Shell of the female excessively tumid ; seen from the side, broadly ovate, with a 

 prominent posterior beak, greatest height in the middle, and equal to two-thirds of the 

 length, anterior extremity fully rounded, and forming a continuous curve with the dorsal 

 margin, which is boldly arched ; posterior extremity produced below the middle into a 

 prominent angular beak ; ventral margin moderately convex ; seen from above, broadly 

 ovate, not twice as long as broad, widest behind the middle, lateral margins extremely 

 convex, converging gently towards the front, and more abruptly backwards, anterior 

 extremity subacuminate, posterior obtuse; end view broad, ovate, widest below the 

 middle, pointed at the apex, sides very convex ; left valve larger than the right. Surface 

 of the shell marked throughout with large circular impressed puncta, hinge-tubercles 

 conspicuous; no very marked encircling fillet. Length, l-28th of an inch ("9 mm.). 



Dredged ofi" St Vincent, Cape Verde, in a depth of 1070 to 1150 fathoms (Station 93), 

 and ofl' Ascension Island, 420 fathoms (Station 344). The tj^o. specimens which differ 

 in nothing from those here described, except in the frequent presence of a spine at the 

 infero-posteal angle, were found in a dredging from Tenedos ; and I have other specimens 

 from Colon and New Providence, and St Vincent, Cape Verde. The species altogether is 

 very like an excessively tumid Cythere convexa, Baird. The distinct inequaHty of size 

 of the right and left valves, in this and the preceding species, is an interesting peculiarity, 



