from the Arctic and Scandinavian Seas. d1 
Cytheridea pulchra, Brady. 
oryza, Brady. 
Bythocythere simplex (Norman) 
(= Jonesia simplex, Brady, 
loc. cit.). 
Cytheropteron latissimum (or- 
man) 
(= Cythere latissima, Brady, 
loc. cit.). 
Cytherura clathrata, G. O. Sars. 
Davis's Straits. 
Lat. 67° 17'N., long. 62° 21' W. 
- 6 feet below low-water mark. 
Cythere lutea, Miiller. 
— villosa (G. O. Sars). 
— tinmarchica (G. O. Sars). 
-— borealis, nov. sp. 
emarginata (G. O. Sars). 
—— angulata (G. O. Sars). 
pulchella, Brady. 
tuberculata (G. O. Sars). 
concinna, Jones, 
Cytheridea papillosa, Bosquet. 
Cytherura rudis, ov. sp. 
Paradoxostoma variabile (Baird). 
Paradoxostoma variabile (Baird). 
Cumberland Inlet, 153 fathoms. 
Lat. 66° 10’ N., long. 67° 15’ W. 
Cythere dunelmensis (Vorman). 
Cytheropteron montrosiense, C. 
B.S R. Iceland (in shell-sand). 
ee Cythere lutea, Miiller. 
Aaa P borealis, nov. sp. 
Cytherura undata, G. O. Sars. emarginata (G. O. Sars). 
(Plate IV. figs. 1-4, 6, 7.) 
Carapace of female, seen laterally, subreniform, 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 antenne 
robust, six-jointed, fourth and fifth joints coalescent, last 
four joints armed with strong, flexuous, apical spines ; fla- 
gellum of lower antennz 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 
zp Inch. 
Cythere borealis, nov. sp. 
