242 





strongly built, with the joints of the terminal part considerably dilated and 

 provided with powerful muscles, apical claw strong, falciform, and shorter than 

 the preceding joint. Copulative appendages with a distinctly projecting chitinou 

 string inside the basal part, terminal part somewhat nose-shaped, with th 

 posterior edge deeply sinuated and the extremity narrowly rounded. 



Colour of shell whitish, semipellucid, and variegated with a few irre 

 gularly arborescent pigmentary patches of a light reddish hue. 



Length of adult female amounting to 1.33 mm. 



Remarks. This is an easily recognisable form, being well distinguished 

 both by the characteristic shape of the shell and by its comparatively large 

 size. It is indeed apparently the largest of all hitherto known Cytheridse. 



Occurrence. I have taken this magnificent Ostracod in many places o 

 the Norwegian coast, from the Oslo Fjord to Lofoten in depths ranging 

 from 20 to 50 fathoms. It is easily detected in the samples examined, both 

 by its large size and by its particularity of remaining floating on the surface 

 of the water, when coming in contact with the air. 



Distribution. British Isles, Hunde Islands, Baffin Bay. 



Fossil. Scotland, Ireland. 







Subfam. 7. Xestoleberinae. 



Remarks. This subfamily is proposed to include the genus Xestoleberis 

 G. O. Sars, which cannot properly find its place within any of the other sub- 

 families here recorded. Another genus, unquestionably referable to this sub- 

 family, has recently been established by G. W. Miiller under the name of 

 Micro Xestoleberis, and I am also of opinion that the peculiar fresh-water genus 

 Metacypris Brady ought to be adduced to the same subfamily. In the struc- 

 ture of the several limbs some accordance may be found with the Cytherinoe, 

 as above defined; but the shell is of a very dissimilar appearance and in 

 particular distinguished by its encompassing behind a roomy breading cavity 

 for the reception of the mature ova during their further development. Only 

 the typical genus is represented in the Fauna of Norway. 



Gen. 48. Xestoleberis, G. O. Sars, 1865. 



Generic Characters. Shell tumid, narrowed in front, with the ventral face 

 distincly flattened behind. Valves slightly unequal, with the surface smooth 



