RECENT BRITISH OSTRACODA. 



461 



Carapace, as seen from the side, elongate siliquose, highest behind the middle ; greatest 

 height equal to much less than half the length. Anterior extremity much narrowed, 

 rounded; posterior produced, and somewhat angular in the middle; superior margin 

 well and evenly arched ; inferior nearly straight in front, convex behind. Outline, as 

 seen from above, ovate, fully thrice as long as broad, broadest in the middle ; extremities 

 equally acuminate. Colour dull yellowish white. The animal, so far as I have been 

 able to ascertain from dried specimens, exactly resembles P. variaMle, except in the 

 various parts being more slender and elongated. 



Length in. 



Hab. In shell-sand^ Girdler Sand, estuary of Thames, and Donegal Bay [Mr. E. C. Davison) ; the Minch 

 {Mr. Jeffreys's dredgings) ; Shetland and Peterhead [Mr. D. Robertson) ; Plymouth, Swansea, and 

 Herm {Rev. A. M. Norman) . 



P. ensiforme appears to be perfectly distinct from any other described species, though 

 in general outline it rather approaches the form of P. variaMle, figured at Plate XXXV. 

 figs. 12, 13. The chief characteristics of the present species are its attenuated and 

 flexuous form, the median angulation of the posterior, and the comparatively slight 

 compression or keel-like projection of the ventral margin. 



9. Paradoxostoma flexuosum, Brady. (Plate XXXV. figs. 30-34.) 



Bythoci/there? flexMosa, Brady, Brit. Assoc. Report, 1866, p. 211. 



Carapace, as seen from the side, sublinear, flexuous, highest in the middle, greatest 

 height equal to one-third of the length ; obliquely rounded, and sloping steeply in front, 

 tapering to an obtusely angular median process behind ; superior margin evenly and 

 gently arched ; inferior sinuated in front, convex and compressed behind. Outline, as 

 seen from above, compressed, ovate, four times as long as broad ; extremities acuminate. 

 Colour yellowish white. Animal unknown. 



Length ^-f si" ^ — 



Hab. Hebrides and the Minch, 45-60 fathoms {Mr. J. G. Jeffreys's dredgings) ; Birterbuy Bay, 10 fathoms 

 (G. S. B.) ; Plymouth {Rev. A. M. Norman) ; Girdler Sand, Thames {Mr. E. C. Davison) . 



10. Paeadoxostoma ? ARCUATUM, n. sp. (Plate XXXV. figs. 37, 38.) 



Carapace, as seen from the side, elongate, curved, highest in the middle ; greatest 

 height equal to little more than one-third of the length ; attenuated and rounded in 

 front, obliquely rounded behind ; superior margin boldly and evenly arched ; inferior 

 sinuated in front of the middle, slightly convex behind ; anterior and ventral margins 

 compressed and marked by radiating trauvsverse lines. Outline, as seen from above, 

 compressed ovate, broadest behind the middle ; greatest width equal to one-fourth of the 

 length. Colour pearly white. Animal unknown. 



Length in. 

 Hub. Birterbuy Bay, 10 fathoms. 



One specimen only found. 



