48 



Vertical Distribution. — The species occurs in greatest numbers 

 in depths of 10-40 fathoms in the Irish Sea ; on the west 

 coast it also extends into deep water down to more than 

 300 fathoms. The Helga took seven specimens, two of them 

 very large, in 337 fathoms, the greatest recorded depth for 

 the species, with the exception of one given by Senna C1903), 

 from the west of Sicily, 416-450 fathoms. 



Genus Nephropsis, Wood Mason. 



Nephropsis, Wood Mason, 1873. Nephropsis, Norman, 

 1882. Nephropsis, Alcock, 1901. Nephropsis, St ebbing, 

 1903. 



The rostrum is fair]}'- long, robust, usually furnished with 

 lateral spines. Carapace more than half as long as the abdomen ; 

 cervical groove very distinct ; telson quadrate. 



The eyes are hidden beneath the rostrum ; they lie close 

 together, are very smal^ and devoid of pigment. The first joint 

 of the antennular peduncle has no stylocerite ; there is no anten- 

 nal scale. First three pairs of legs chelate ; first pair large and 

 massive, very slightly unequal in both sexes ; second pair 

 slightly stouter than the succeeding pairs. 



Nephropsis atlantica, Norman. 



PI. VII, figs. 1-13. 



Nephropsis atlantica, Norman, 1882. 

 Nephropsis atlantica, Caullery, 1896. 

 Nephropsis atlantica, Alcock, 1901. 

 Nephropsis atlantica, Hansen, 1908. 



The surface of the carapace is granular and bears a fairly 

 dense coating of hair. The large rostrum, shghtly upturned 

 near the tip, is about half as long as the carapace ; it bears a 

 fringe of setae low down on either side. Normally it has two 

 pairs of large lateral spines, but occasionally there are three 

 pairs, and sometimes two on one, and only a single spine on the 

 other side. At the base of the rostrum there are two large spines 

 directed outwards and forwards, and behind these, two smaller 

 ones. Between these two pairs there is a double divergent row 

 of small teeth which decrease in size backwards. Enclosed by 

 these, on the median line there is a blunt oval tubercle. At 

 each side there is a large spine over the base of the antenna. 

 There is a slight furrow running along the median line from 

 the rostrum to the very prominent cervical groove ; behind the 

 latter it becomes much fainter, but can be traced to the posterior 

 margin of the carapace, which is slightly concave. A distinct 

 ridge divides the cardiac from the branchial area. From the 

 posterior angle of the carapace there runs a very prominent 

 ridge downwards and forwards parallel to the latero-ventral 



