1910.] BRITISH SPECIES OF OSTRACODA. 209 



Oandonopsis kingsleu Brady & Robertson. 



1870. Candona kingsleii Brady & Robertson, (8) p. 17, pi. ix. 

 figs. 9-12. 



1889. Candona kingsleii Brady & Norman, (2) p. 102, pi. ix. 

 figs. 19, 20 (not 21, 22), & pi. xiii. fig. 13. 



1891. Oandonopsis kingsleii Vavra, (6) p. 54, fig. 16. 



1900. „ „ G. W. Midler, (5) p. 38, pi. vi. figs. 



6, 7, 23-28 ; pi. vii. figs. 22-25. 



This seems to be a widely distributed species. It is of frequent 

 occurrence in the Fen district of England, and in Scotland ; 

 perhaps less frequent in other parts of England, but may very 

 possibly have been often confounded with other nearly allied 

 forms. This is undoubtedly the case with some Scottish speci- 

 mens, which, though supposed to belong to C. kingsleii, are 

 really Candona protzi. Others belong to the form here described 

 as Candona caledonice. 



Oandonopsis scourfieldi, sp. n. (Plate XXYI. figs. 1-12.) 



Male. — Length - 85 mm. Shell, seen from the side, oblong, 

 subreniform (fig. 1), greatest height situated in the middle 

 and equal to rather less than half the length, extremities 

 equally and evenly rounded ; dorsal margin gently arched, sloping 

 gradually towards each extremity, ventral almost straight : seen 

 dorsally (fig. 2) the outline is much compressed, widest in the 

 middle, the width being equal to one-fourth of the length., extrem- 

 ities sharply produced, acuminate. Surface of the shell smooth, 

 slightly hairy near the extremities ; the free margins of the 

 valves when seen by transmitted light are marked with a single 

 row of minute dark pigment spots (fig. 12). Anterior antennas 

 slender, six-jointed, the last four joints provided with long, 

 delicate setae ; posterior antennae five-jointed (fig. 3), the basal 

 joint bearing a slender triarticulate sense-organ (fig. 4), second 

 joint having at the extremity of its inner margin a single long- 

 seta which reaches considerably beyond the apex of the limb, third 

 joint provided with a fascicle of three short setae, fourth and fifth 

 joints each bearing two stout setae but no claws ; mandible-palp 

 elongated, and otherwise having the typical characters of the 

 genus (fig. 5) ; second pair of maxilla? prehensile, clawed, that of 

 the right side the more robust (fig. 6) ; second pair of feet bearing 

 at the apex (tig. 8) two seta? of unequal length. Caudal rami very 

 slender (fig. 9), the two terminal claws not quite equal in length, 

 no marginal seta : the penis rather small and compact, oblong, with 

 two subtriangular apical laminae (fig. 10) ; ejaculatory duct very 

 broad and massive, enclosed in a dense, transversely striated 

 capsule (fig. 11). The female does not differ materially from the 

 male except in purely sexual characters. 



I am indebted to my friend Mr. D. J. Scourfield for two speci- 

 mens — male and female — of this very interesting species. They 

 were taken in Catfield Fen, Norfolk. 



Proc. Zool. Soc— 1910, No. XIV. 14 



