from the Arctic and Scandinavian Seas. 



31 



Cytheridea pulchra, Brady. 



oryza, Brady. 



Bythocythere simplex (Norman) 

 (= Jonesia simplex, Brady, 

 loc. eit.). 

 Cytheropteron latissimum (Nor- 

 man) 



( = Cythere latissima, Brady, 

 he. eit.). 

 Cytherura clathrata, G. O. Sars. 

 Paradoxostoma variabile {Baird) . 



Cumberland Inkt, 15| fathoms. 

 Lat. 66° 10' N., long. 67° 15' W. 

 Cythere duuelmensis (Norman). 

 Cytheropteron montrosiense, C, 

 B.^B. 



vespertilio (Beuss). 



infiatum, C. B. Sf B. 



Cytherura undata, G. O. Sars. 



Davis's Straits. 



Lat. 67° 17' N., long. 62° 21' W. 



6 feet below low- water mark. 



Cythere lutea, Mi'dler. 



villosa (G. O. Sars). 



tinmarchica (G. O. Sars). 



borealis, nov. sp. 



emarginata (G. O. Sars). 



angulata (G. O. Sai's). 



pulchella, Brady. 



tuberculata (6^. O. Sars). 



concinna, Jones. 



Cytheridea papillosa, Bosquet. 

 Cytherura rudis, nov. sp. 

 Paradoxostoma variabile (Baird). 



Iceland (in shell-sand). 

 Cythere lutea, Muller. 



borealis, 7iov. sp. 



emarginata (G. O. Saj's). 



Cythere horealiSj nov. sp. (Plate IV. figs. 1-4^ 6, 7.) 



Carapace of female, seen laterally, snbreniform, highest in the 

 middle ^ greatest height equal to more than half the length : 

 anterior extremity obliquely rounded ; posterior subtruncate, 

 somewhat emarginate above the middle : superior margin 

 arched, inferior sinuated in front of the middle. Outline, 

 as seen from above, ovate, widest in the middle, extremities 

 obtusely mucronate ; width equal to half the length. The 

 right valve differs from the left in shape, being higher, 

 with the dorsal margin more boldly arched, distinctly 

 excavated in front of the eyes, and much more conspi- 

 cuously emarginate behind. The hinge-joint is formed, in 

 the left valve, by a crenulated median bar, with a mode- 

 rately strong anterior tooth-like process ; in the right valve 

 by a small anterior tooth and a slightly crenulated posterior 

 projection. The shell of the male is longer and narrower, 

 with the anterior margin produced downwards and nume- 

 rously serrated. Surface of the valves covered with shallow, 

 rounded (and often distant) pits, but not at all ridged or 

 tuberculated. Colour yellowish brown. Upper antennae 

 robust, six-jointed, fourth and fifth joints coalescent, last 

 four joints armed with strong, flexuous, apical spines ; fla- 

 gellum of lower antennas in the female short and robust. 

 Feet long and strong ; second joint of last foot shorter than 

 the two succeeding joints, terminal claws long and pectinated 

 on the concave border. Male copulative organs of mode- 

 rate size, posterior segment obtusely triangular. Length 



* inch. 



^9 



