RECENT BRITISH OSTRACODA. 



409 



varieties of this fine species, I must refer the reader to a Monograph of the Posttertiary 

 Entomostraca which is in preparation for the Palseontographical Society. 



17. Cythere angulata (Sars). (Plate XXVI. figs. 39-42.) 



Cythereis angulata, Sars, loc. cit. p. 40. 



Scandinavian type. Distribution : Recent — Baffin's Bay, Norway, Great Britain. Fossil — Glacial and 

 raised beaclies, Scotland and Norway. 



Carapace, as seen from the side, oblong, quadrilateral, greatest height near the front, 

 and equal to more than half the length. Anterior margin rounded below and sloping 

 steeply backwards above; posterior narrower, rectangularly truncate, and somewhat 

 protuberant below the middle ; ventral margin nearly straight, dorsal sloping backwards 

 in a straight or gently curved line from the anterior hinge. Outline, as seen from above, 

 very irregular, somewhat lozenge-shaped, tapering slightly towards the front, which is 

 very obtuse or almost truncate, the sides parallel and constricted in the middle ; posterior 

 extremity broadly and obtusely mucronate, greatest width equal to less than half the length, 

 the hinge-margins forming at their junction a narrow, sharply cut longitudinal sulcus. 

 End view broadly ovate; deeply constricted above the middle; broad above, sharply 

 keeled below. Surface irregularly undulated and marked with angular excavations of 

 variable size ; a conspicuous rounded tubercle near the anterior hinge, and another large 

 rib or elongated tubercle near the centre of the valve ; a sharply defined transverse ridge 

 terminates the sculptured portion of the shell, beyond which the posterior portion projects 

 on a lower level. The right valve is rather smaller and more angular than the left, and 

 the dorsal margin is more depressed. Colour brown. " Third and fourth joints of the 

 upper antennae confluent, the last short and armed with a strong spine. Second joint of 

 the last foot much shorter than the two following. Copulative organs of the male small, 

 apical portion obtuse, subhamate." 



Length 3^ in., height in. 



Hab. The Mincli, 45-60 fathoms [Mr. J. G. Jeffreys) ; Shetland, Lerwick, Cumbrae, Macduff Harbour, 

 and Peterhead {Mr. D. Robertson) ; Scarpa Flow, Orkney [Mr. E. C. Davison). 



This is very distinct from any other recent British species, and is apparently one of 

 the rarest. Sars notes that specimens from Pinmark are much larger and more abundant 

 than those found by him in Christianiafiord ; he therefore infers that it is a peculiarly 

 northern species. It occurs in the glacial clays of Scotland and Norway. 



18. Cythere dubia, n. sp. (Plate XXXII. figs. 75, 76.) 



Carapace, as seen from the side, subquadrangular, highest in front, greatest height 

 equal to more than half the length. Anterior extremity rounded, posterior obliquely 

 subtruncate, angulated about the middle, below which are three small teeth; superior 

 margin slightly convex, sloping almost in a straight line to the posterior extremity, where 

 it forms an abrupt angular projection ; inferior deeply sinuated in front of the middle. 

 Seen from above, the outline is irregularly subovate, about twice as long as broad ; sides 



VOL. XXVI. 3 K 



