RECENT BRITISH OSTRACODA. 



459 



claws unequal, one large, the other very short and slender. Terminal claw of third 

 foot long and slender, finely ciliated on the anterior margin ; the preceding joints not 

 ciliated. 



Length ^5- in. , S^S' — 

 Hab. Isle of Skye, Herm, and Plymouth {Rev. A. M. Norman). 



4. Paradoxostoma ptjlchellum, G. 0. Sars. (Plate XXXV. figs. 41, 42.) 



Paradoxostoma pulchellum, G. 0. Sars, loc. cit. p. 95. 



Carapace of the female much compressed; seen from the side, nearly semicircular, 

 rather more tapered in front than behind ; greatest height in the middle, and equal to 

 rather less than half the length. Extremities rounded, the anterior rather the narrower 

 of the two ; superior margin evenly arched, inferior very slightly sinuated in the middle. 

 Outline, as seen from above, much compressed, nearly four times as long as broad. Shell 

 pellucid, yellowish, with deep-black or violet dendritic markings scattered irregularly 

 over the dorsum and centre of the valves. " Third joint of the upper antennae scarcely 

 shorter than the preceding, and longer than the following ; last two subequal, their united 

 lengths not shorter than the preceding one. Lower antennae very slender, bearing one 

 small terminal claw. Jaws and feet almost as in P. abbreviatum. Male unknown." 



Length in. , r -— - 

 Hab. In rock-pools, Guernsey, Herm, and Stornoway {Rev. A. M. Norman). 



A very distinct and pretty species, well worthy of the name bestowed upon it by Sars. 

 The colouring of the specimens collected by Mr. Norman does not exactly agree with 

 Sars's description (" in medio vero fascia lata transversali colore saturate obscure-violaceo 

 instructae), though in some cases there is an indication of a transverse band; but very 

 little stress can be laid upon this point, especially in the present genus. 



5. Paradoxostoma obliqutjm, G-. O. Sars. (Plate XXXV. figs. 18-21.) 



Paradoxostoma obliquum, G. O. Sars, loc. cit. p. 97. 



Carapace of the female tumid, seen from the side subrhomboidal ; greatest height in 

 the middle, equal to more than half the length. Anterior extremity rounded, much 

 narrowed; posterior obliquely truncate, its upper angle produced; superior margin 

 strongly arched, sloping steeply in front, where it is also slightly incurved ; inferior gently 

 convex. Outline, as seen from above, ovate, fully twice as long as broad. End view 

 nearly circular. The right valve is of a shape different from the left, being higher and 

 overlapping on the antero-dorsal and postero-ventral margins. 3Iale unknown. Shell 

 smooth, pellucid, fawn-coloured, without any maculae. 



Length -^5- in. , ^ /'v — 



Hab. Abundantly in shell-sand from Roundstone {Dr. Alcock) ; in oyster-ooze from Stranraer {G. S. B.) ; 

 Sound of Skye, and in tide-pools at Arran, N.B., and Herm {llev. A. M. Norman) ; Shetland {Mr. 

 D. Robertson). 



Of this very well-marked species I have been able to dissect only one specimen (Stran- 

 raer), and the animal was not in sufficiently good preservation to enable me to do 



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