RECENT BRITISH OSTRACODA. 





ventral margin sinuated in front, very convex behind. The valves are bordered by a 

 broad, flattened flange, which bulges conspicuously near the middle of the ventral margin, 

 and is lost on the dorsum; the flange is marked by numerous closely set radiating hair- 

 like lines. Outline, as seen from above, elongate fusiform, more than thrice as long as 

 broad, narrowed in front, slenderly acuminate behind, the right valve overlapping the 

 left. Shell of the male scarcely different from that of the female. Lucid spots five, 

 forming an oval patch a little below and in front of the centre of the valve ; spots parallel, 

 the three central ones linear-oblong, the terminal ones oval or lenticular. Shell perfect ly 

 smooth, thin and structureless, pellucid, slightly olivaceous, with arborescent markings 

 of a deeper tint. Hinge-margins straight, quite simple. Last pair of feet in the male 

 subprehensile, last three joints very robust, terminal claw very strong. Distal portion of 

 the male copulative organs large, irregularly triangular, subtruncate at the apex ; anterior 

 margin straight, posterior deeply sinuated. No eyes. 



Length of female ■£$ in. 



Northumberland 



M. 



M 



the Mincli 



w- 



This species was first described by tbe Rev. A. M. Norman, from specimens taken „. 

 deep water a hundred miles off the coast of Northumberland, and shortly afterwards b 

 G. 0. Sars from Norwegian specimens. Though widely distributed, A seems o be 

 point of numbers, rather a scarce species, the only British gatherings in v , hie i 1- 



all abundantly being those from the Aberdeenshn, coa and i- 



ed at 



Scarborough. It occurs in the Arctic seas, and also in a fossil state m the Scotch 



clay 



(1 



2. Bythocythere constricta, GL 0. Sars. (Plate XXXV. figs. 17 52.) 



Bythoajthere comtricta, G. O. Sars, he. cit. p. 85. 



Carapace tumid, expanded into an obtusely angular lateral pMuberan ^ 



slightly constricted in the middle; ventral surface ^Jf'^i front ; greatest 

 seen from the side, subrhomboidal, rather higher behind ia ^ 



height equal to rather more than half the length ; °^™^ e ™ Muntl £oo.hod) 

 behind above the middle into a short, obtusely round d («j£» m ^ 0ut . 

 process. Dorsal margin nearly straight ; ventral sinua e . nate lic , hind . 



line, as seen from above, ovate, widest behind the middle, sUo^ y ^ ^ ^ ^ 

 greatest width equal to considerably more than hall . ^ _ S .^ ^ ^ ^ 

 as seen from the side, much more elongated, nign ' ate and less produced 



less than half tbe length; posterior extremity •JW^.tf punctat ions, which are 

 above. Surface of the shell marked with rather i ■ , ^ ^^ ^ producin g a 

 connected with each other by more or less distinc , t bearin „ nume rous floccu- 



faint reticulation ; ventral surface longitudinally striate ,, ^^ ^ ^^ ^ 

 lent white papillce; infero-posteal angle armed (Irequ '' Second joint, of 



Penultimate joint of the upper antennai longer tnan t g ^ 



| T 



u 



