RECENT BRITISH OSTRACODA. 



U5 



This species bears considerable resemblance to Prof. T. It. Jones's Ji-ures of C. reti/a*- 

 tigiata, but a reference to the type specimens, kindly placed at my disposal by that 

 author, convinces me that the two species are quite distinct. The more elongated lb nns 

 figured at 31 and 36 are very probably, as in other species, the males; but I have not 

 been able to satisfy myself of this, all the specimens which I have examined bavin 

 proved to be only empty shells. 



27. Cytherb mirabilis, nov. sp. (Plate XXIX. figs. 7, 8.) 



Distribution : Recent — Scotland. Fossil — Glacial, Scotland. 



Valves, as seen from the side, subtrapezoidal, highest at the anterior third; gmtot 

 height equal to two-thirds of the length. Anterior extremity broadly and ohliquch 

 rounded, its lower half bearing a series of short blunt teeth; posterior narrow, vrv 

 slightly curved, bearing four teeth at the lower angle; superior margin sloping steeply 

 and in a convex line from before backwards, terminating abruptly in an obtuse an le at 

 each extremity, more or less abruptly undulated or emarginate throughout, but especially 

 behind the anterior extremity, where it is twice or thrice deeply and irregularly jagged ; 

 inferior margin evenly convex. Outline, as seen from above, ovate, twice as long as 

 broad, obtusely toothed and mucronate behind, margins irregular lv spinous and emar- 

 ginate. Hinge-joint very strongly developed, consisting in the right valve of a triangular 

 tooth in front and an obliquely truncate one behind; in the left of a strong central bai 

 ending abruptly behind, and elevated into an angular tooth in front. Surface of th« 

 shell covered in its central and middorsal portions with large angular excavations, and 

 surrounded on the ventral margin and the extremities by wide and sharply cut Irre- 

 gularly concentric furrows, across which the separating ribs anastomose sparingly. 



Length -Jj in. 



Hab. Off Lumpan Head, Lewis (Admiralty soundings) . 



I have seen only one valve of this species in a recent state; some of the details above 

 given are taken from fossil specimens obtained from the Scotch Glacial clays. 



28. Cythere mtjcronata (G. 0. Saw). (Hate XXVI. figs. 34, 31 a.) 



Cythereis mucronata, G. O. Sars, loc. cit. p. 48. 



figs 



Shetland 



ed 



Scandinavian type. Distribution : Recent 



Valves, as seen from the side, subquadrangular, highest in front of the middle , greatest 

 height equal to half the length. Anterior margin rounded, fringed wi h six T«y broad 

 strong, linguiform, obtusely rounded spines ; posterior narrower, frmged also with - — 

 of about nine much smaller and abruptly truncated spines; superior marg, n 

 Regularly emar-inate inferior nearly straight. The eentral port.on of tl e v,l e 8 



o j cuicii iii<u,e, uuraiu j „„„„u r nrotubera uces, which, toward the 



closely beset with large, elumsy, irregularly angular protu , 



xtremities, are much fewer and smaller ; along he cntral u > f ^^ 



stout tooth-like spines, the last of which projects strong o 



