RECENT BRITISH OSTRACODA. 



403 



Lucid spots about eight in number, subquadrangular, and arranged in two irregular 

 transverse rows. Two small shining eye-tubercles. Superior antenna robust, iive- 

 jointed, second joint short, not much more than equal in length to the two succeeding; 

 last joint short; terminal spines strong, curved. Inferior antennae robust, last joint 

 short and truncate, terminal claws rather short and slender; urticating seta reaching 

 to about the apex of the limb, equal in the male and female ; penultimate joint, in the 

 male, deeply emarginate about the middle of the posterior margin and bearing three Bete, 

 one of which is short and slender, the central one longer and strongly pectinate, the other 

 very short and club-shaped (see Plate XXXIX. fig. 3ft). This arrangement is similar in 

 the female, but all the parts are feebly developed. Second joint of the last foot not much 

 longer than either of the two succeeding joints. Terminal claw long and strong. Abdo- 

 minal lobes truncate, each bearing two ciliated terminal setae. Eyes two. Basal portion 

 of the male copulative organs very large, quadrate ; apex acute and tapering. 

 Length -^- in., height -fe in. 



Hal,. Littoral and in moderate depths up to 15 fathoms, 'in shell-sand from Walton .ml VI,iMal,l« 

 [Prof. T. Rupert Jones); Orkney, Girdler sand (Thames), Margate, and Cork [Mr h. C.Dan,,,, 

 Shetland, Loch Carron, Arran (N.B.), Tobermory, Youghall, Exmouth, Burrow Island, Guernae, 



M. 



Cnmhrae, Macduff, and Peterhead (Mr. D. Robertson) ; Aberdeenshu-c coast^ , —'"''"'"; 

 ' Rounds* ne, and Birterbuy Bay (dredged), and abundantly in rock-pool, at *—*"*££ 

 Durham coast, and in shell-sand from the Mumbles and Stranraer (G. S. B.) , Norfolk coast, dredg, 



(Mr D O Drewett). 



The form described by Dr. Baird under the specific name alba (see fig. 38«) seems to 



be the young of Cy there Mom-**. 0. strigulosa, Benss m very close* aU^to, 



but (accord^ to specimens named by M. Bosouet) not identtcal tnth the pr «*nt spec „ 

 C. aloomacuL differs remarkably from most of those with winch ,t is as cd m th 

 form and structure of the shell, the peculiar armature of the second nten ^ and U 

 structure of the mandibular palp, the latter being <pte similat ■ to the fa n Wrf 





the following section 



hich includes the species usually classed under the 



,,, c luuuHmg ma^.1, ..—- j n not seem so much so as to warrant uic 



Oytherei,. These differences, though important, J™*"" most abun(1;mt 



formation of an independent genus for has ^J^^Kl "found all round our 

 and most widely distributed of the Bntish marine OM^- « , kable ^ ^ 



coasts from biah-water mark to a depth of about lo Lthoms ™T 



apparent absence 



large and 



vater mam iu <* ^ continental Europ 



from the Scandinavian and Jjjto^ ^.^ ^ ^ 



_ „ conspicuous ^^^^Should further observation show 



naturalists as have recently investigated t his b iou ? & ^ interesting , and 



that its distribution is confined to f^^*^ attaill cd almost a predomi- 

 perhaps a unique example of a purely Bntisn *P^ . ° occurg in the „ lacia l c l ays 



and number 



nant position in its own district as to range ana n ~ ^^ of R 



nf +!,;„ __x__ i_x t ~~. „«* nwjirft whether it hah oeen iwu 



of this country, but I am not 



Robertson 



•oiil^C 11113 MJIS 111 tilt lllllli.v.1 " •— ' 



Norway, and others from the Mediterranean. 



3i2 





