RECENT BRITISH OSTRACODA. 



391 



highest in the middle, and sloping steeply behind; ventral gently sinttated in front, and 

 htly convex behind. Seen from above, the outline is compressed, oval ; extremith - 

 equally and rather obtusely pointed; greatest width in the middle, equal to about one- 

 third of the length. Hinge-line slightly sinuous. The left valve overlaps considerably 

 on the dorsum and in the middle of the ventral surface. Shell smooth, colour pale 

 ochreous or white, opaque. Auimal unknown. 

 Length -^ in., height ■£% in. 



Sab. The Minch, 45-60 fathoms {Mr. Jeffreys) . 



This very fine and distinct species occurred in the same dredgings with B. obtu$ata, 

 and though more abundant than the latter species, must still be considered rare. 



Genus 8. Macrocypris, Brady 



* 



Carapace much elongated, attenuated at the extremities. Valves unequal, the right 

 larger than the left, and overlapping dorsally; hinge-line flexuous. Surface smooth, 

 polished, and destitute of hairs. Antenna? short and robust, the superior seven-jointed, 

 joints tapering towards the apex, bearing short setae; the inferior composed of tore 

 distinct joints, last two joints very short; armed with much-elongated claws; second 

 joint bearing on its inner side near the base a bundle of short Particulate setae. Man- 

 dibles large, dilated at the inferior extremity, and divided into six or seven stron 



D 



l- 



teeth ; palp elongated, four-jointed, and having a distinct branchial append 

 pair of jaws provided with an unusually small subovate branchial plate; external lobe 

 or palp narrow, not larger than the rest. Seconu pair of jaws destitute of a branchial 

 appendage ; palp, in the female, large and subpediform, composed of four distinct joints, 

 the last armed with three claws or spines ; in the male very robust and subchchform. 

 First pair of feet much elongated, five-jointed, last joint armed with one or two Iodl- 

 forward-curved claws; the second pair very different, and covered entirely by the shell, 

 five-jointed, last joint armed with a very long recurved claw. Postabdommal ram, 

 rudimentary, forming two small and simple appendages attached to the posterior part o 

 the abdomen. No eye. Male smaller than the female ; copulative organs lai e and 

 provided at the anterior extremity with a much-elongated mucus-gland 



The species constituting this genus are included by Saw under Bou-tlu, ; that author, 

 however, had had no opportunity of examining the animals belonging to the group 

 typified by B. subdeltoid, to which the name Bairdiu was ongma ly given by M Co> 

 I have myself so far succeeded in the investigation of the animal s ructur" - m£, 



ample generic characters in the formation of the postab omen, »»£»*£*■ ?*£ 

 m..° , ii,+ "Rut m addition to peculiarities oi animal 



of its anatomy remain to be worked out. But, in aacn i 



L . J . n i- a A /Kffprences. in its attenuated iorm ana in 



structure, the carapace presents well-marked differences, m 



the respective size of the valves, the right being here much the larger. 



Bars observes that this marine genus seems to be -^««^ ^ % *J 

 Canclona, just as Pontocypris appears to be the marine equivalent of <&».. 



only British species is 



as to find 



• D. 119. 



xu 



