1910.] BRITISH SPECIES OF OSTRACODA. 201 



processes of the abdomen are sharper and more elongated, while 

 there are also some slight differences in the setae of the limbs. 

 Another nearly allied species is G. prolzi Kanfmann, but here 

 the differences are more conspicuous. 



It therefore seems necessary to adopt a new name. It is 

 probable that if male specimens were forthcoming, serviceable 

 characters might be found, but none except females have hitherto 

 been observed. 



In addition to the localities mentioned in the Monograph (loo. 

 cit.) I have found G. siliquosa in Barton Broad, Norfolk, and in 

 ponds near Lyndhurst, Hants. Dr. T. Scott has taken it in many 

 Scottish waters. 



Candona elongata Brady & Norman. (Plate XXII. figs. 1-8.) 



1889. Candona elongata B. & N. (2) p. 100, pi. x. figs. 26-27. 



1891. „ „ (?)Yavra, (6)p. 111. 



Female. Length 1-3 mm. Shell, seen laterally, reniform, 

 greatest height situated in the middle and equal' to about half 

 the length ; extremities rounded, the anterior narrower than the 

 posterior ; dorsal margin evenly arched, ventral only slightly 

 sinuated (fig. 1) : seen clorsally the outline is rather narrowly ovate 

 (fig. 2), pointed acutely in front, less acutely behind, width scarcely 

 equal to half the length ; left valve somewhat larger than the right 

 and overlapping at the extremities. Surface of the shell smooth, 

 colour brown. 



The anterior antennae are short and stout (fig. 3), the individual 

 joints also short, all but the last two broader than long ; the setae 

 also short and stout, the three longest not as long as the antennule 

 itself, the rest very much shorter ; mandible-palp very short and 

 stout (fig. 5) ; palp of the second maxilla more than usually dilated ; 

 terminal joints of the second pair of feet short and stout (fig. 7). 

 Caudal rami robust and curvate (fig. 8), the two apical claws 

 nearly equal in length ; the marginal seta moderately long and 

 situated considerably beyond the middle of the limb. 



In the original description of G. elongata, it seems probable 

 that two quite distinct species have been taken as representing the 

 two sexes, but it is impossible at present, owing to want of 

 specimens, to clear the matter up. Lough Neagh, where the 

 species was taken years ago by the Rev. Canon Norman, is up 

 to the present the only known British locality for it, though 

 specimens referred to it have been found in Bohemia by Herr 

 "Vavra. Dr. Y^avra, however, writes to me that his supposed 

 specimens of C. elongata were identified by the late Herr Hartwig 

 as belonging to G. protzi. 



The species is very closely similar to G. siliquosa; but the limbs 

 generally are much more robust and the individual joints thicker 

 and shorter ; the caudal rami are stouter and more curvate, and 

 the genital prolongation of the abdomen, which is so conspicuous 

 in G. siliqitosa, seems to be entirely absent. The shell is slightly 

 larger than that of G. siliquosa. 



