RECENT BRITISH OSTRACODA. 



383 



ornament of the shell is not noticed by Lilljeborg, and is, indeed, visible only in spe- 

 cimens of moderate age, while they remain free from opacity. 



4. Candona CANDIDA (MiiUer). (Plate XXV. figs. 1-9, Plate XXXVI. fig. 13, and Plate 

 XXXVII. fig. 1.) 



Cypris Candida, Miiller, Entomostraca^ p. 63, tab. vi. figs. 7-9; Zenker, Anat.-syst. Studien, p. 76, 

 Taf. i. figs. 1-10. 



Monoculus candidus, Jurine, Hist, des Monocles, p. 176, pi. xix. figs. 7, 8. 

 Candona lucens, Baird, Brit. Entom. p. 160, tab. xix. fig. 1. 

 (?) similis, idem, ibidem, p. 162, tab. xix. figs. 2, 2a. 



Candida, Lilljeborg, De Crust, ex ord. trib. p. 127, tab. xi. figs. 19, 20, tab. xxv. figs. 13-15 ; Jones, 



Tertiary Entom. p. 19, pi. i. figs. 8a-8 /, 5 a, 5 b. 



Valves oblong, lower in front than behind, reniform in the male, subtriangular in 

 the female ; greatest height equal to more than half the length. Anterior margin 

 rounded and narrow. Posterior margin obliquely rounded and produced into a more or 

 less prominent angle inferiorly. The ventral margin is only slightly sinuated in the 

 young and in adult female specimens, but in old examples and in the adult male is 

 deeply sinuated at the anterior third, and bulges considerably behind (figs. 7, 8). The 

 dorsal margin is highest at the posterior third, from which it slopes, in a flattened arch, 

 to the front. The outline, as seen from above, is oblong-ovate, pointed in front, and 

 rounded behind, widest in the middle ; greatest width equal to half the length. End 

 view broadly ovate, somewhat angular at the base, and rounded above. Lucid spots six, 

 oblong, their long diameters nearly parallel to that of the shell, arranged in two lines — 

 an anterior transverse row composed of four spots, and a posterior row of two, placed 

 directly behind the lower spots of the front row. Surface of the shell smooth, pearly or 

 yellowish white, with darker yellow cloudings toward the dorsal margin. Young spe- 

 cimens are regularly oval, and present none of the angulation characteristic of the adult. 

 The setae of the upper antennae are very short, and arranged as in Cypris. The claws of 

 the lower antennse are long and slender. The mandibles and maxillse do not difi'er from 

 those of Cypris, except in the absence of the branchial appendage of the second pair 

 of maxillae. The palp of the second jaw in the male is pediform, ending in one 

 strong curved claw and two shorter ones, which spring from the inner border of the last 

 joint ; the central part of the joint has a curious oval depression, perhaps indicating a 

 muscular attachment ; the palp in the female is subcorneal, and ends in three slender 

 setse. The second foot terminates in three setae, two moderately long, the other rather 

 shorter; the penultimate joint bears one apical seta. Postabdominal rami slender; the 

 two terminal claws slender, and nearly equal in length ; one short posterior seta, and 

 one on the inner margin of the ramus below the middle. Testis composed of a central, 

 cylindrical, transversely striated axis, bearing seven whorls of tapering filaments. The 

 spermatozoids seem to be composed of two filaments, either spirally intertwined or laid 

 side by side (see Plate XXXVII. fig. 1 1). Some large adult specimens, collected by Pro- 

 fessor T. Hupert Jones in slightly brackish water at Gravesend, exhibit near the pos- 

 terior extremity of the shell a peculiar reticulated pattern (fig. 9), very similar to that of 



