23 



moving them, the basal joint is much dilated, not only in the 2 anterior pairs, 

 but also in the 2 succeeding pairs. The 3rd pair of legs, as in several other 

 male Cumacea, are moreover characterised by the presence of 2 peculiar, smooth, 

 falciform spines appended to the inside of the ischial joint, and much resembling 

 those found in the adult male of Laicon nasicus (= - Leuconopsis ensifer Walker). 



Occurrence. I have found this beautiful form rather frequently along the 

 whole south and west coasts of Norway, and occasionally also off the Finmark 

 coast as far as Vardo. It generally occurs in moderate depths, from 20 to 50 fathoms, 

 on a muddy bottom. Owing to the abundant supply of natatory organs, the adult 

 male moves with great agility through the water, whereas the female leads a 

 much more sedentary life on the bottom. 



Distribution. British isles (Norman). 



4. Hemilamprops assimilis, G. 0. Sars. 



(PI. XV.) 

 Hemilamprops assimilis, G. 0. Sars, Oversigt af Norges Crustaceer I, p. 55, PL 1, figs. 23, 24. 



Specific Characters. Very like the preceding species as to external ap- 

 pearance, but with the eye imperfectly developed, without corneal lenses, and 

 having the pigment whitish. Inferior antennae of male extending about to the 

 end of the penultimate caudal segment. 1st pair of legs somewhat less slender 

 than in H. rosea. with the penultimate joint scarcely as long as the 3 preceding 

 joints combined; 3rd pair in male with the 2 peculiar spines of the ischial joint 

 more slender, not falciform, their distal part closely annulated and denticulate 

 on one side. Uropoda nearly as in H. rosea. Telson, however, more narrowed 

 distally, with only a single pair of slender lateral spines, apical spines only 6 in 

 number, the 2 outermost much longer than the others, which are about equal- 

 sized. Body in both sexes semipellucid, without any pigmentary ornament. 

 Length of adult female 5 mm., of male 6 mm. 



Remarks. This species is very nearly allied to H. rosea, though easily 

 distinguishable by the rudimentary condition of the visual organ, as also by the 

 absence of the beautiful pigmentary ornament constantly found in that species. On 

 a closer comparison, some other slight differences are also to be found in the 

 structure of the several appendages, proving the validity of the species. 



Occurrence. I have only met with this form off the Finmark coast, at 

 Vardo, Hammerfest and Hasvig, in depths varying from 60 to 200 fathoms. 

 It is accordingly a much more pronounced deep-water form than the preceding 

 species. Out of Norway, this form has not yet been recorded. 



