706 Brady and Nokman — Monograph of the Marine and Freshwater Ostrncoda 



seta-tipped laminar aj)pendage, second joint with lateral and terminal setae. 

 Incisive portion of the first maxilla (PI. Lxvii., fig. 3) forming a small unguiferous 

 and setiferous lobe, and bearing a veiy large foiir-jointed palp, from the second 

 joint of which springs a large laminar appendage, which together with the palp 

 itself is densely setiferous at the apex. Second maxilla (PL lv., figs. 14, 15) 

 three- jointed, first two joints very massive, last slender, and giving origin to a 

 single stout apical seta ; to the basal joint is attached a semi-elliptic, seta-edged 

 branchial plate. Caudal laminae (PI. lv., fig. 16) having the ungues set in deep 

 incisions of the margin, which is projected between the bases of the ungues in 

 conspicuous j)rocesses. 



Polycope orbicularis, G. 0. Sars. 

 (PI. Liv., figs. 9, 10; PI. LV., figs. 12-16; PI. lxvil, figs. 1-3.) 



1865. Poll/cope orbicularis, . . Sars, Gr. 0., " Oversigt af Norges marine Ostra- 



coder," p. 122. 

 1868. ,, „ . . Beady, " Monog. Recent Brit. Ostr.," p. 471, 



pi. xxsv., figs. 53-57. 

 1874. „ ,, . . Brady, Ceosskey, and Robeetson, " Monog 



Post-Tertiary Ostracoda," p. 219, pi. xii., 



figs. 22, 23. 



Shell of the female, seen from the side almost circular, greatest height situated 

 in the middle, and nearly equal to the length, posterior extremity well rounded, 

 anterior narrower, and slightly exserted, dorsal margin strongly arched, almost 

 angulated in the middle, ventral evenly and rather boldly arched; seen from 

 above the outline is broadly sub-rhomboidal, widest in the middle, the width 

 equal to considerably more than half the length, extremities equal and obtuse. 

 Sui'face of the valves covered with closely-set small circular impressed puncta, 

 and marked with a polygonal reticulated pattern, the ventral margin fringed with 

 small sharp spines or setae. Colour yellowish, mottled with reddish spots or 

 patches. 



Antennules (PI. lxvii., fig. 1), three- jointed, basal joint very massive, pyriform, 

 front margin finely ciliated, and bearing one small seta, second and third joints 

 small, especially the last, the penultimate with one small terminal seta, the last 

 having five setae, which exceed in length the whole limb. Antennae (PI. lxvii., 

 fig. 2) with the basal joint very broad and massive, chief natatory branch 

 nine-jointed, basal joint without seta, shorter than combined length of following 

 joints, remaining joints broader than long, joints 2-8 each with one long natatory 



