neAv to or rare in the British Seas. 97 



antennal scale, per?eopods, &c. ; but it attains a larger size, 

 19 millim. as against 10 millim. Tlie following are points of 

 distinction : — Last joint of peduncle of antennules with three 

 setas on inner margin ; antennal scales perhaps rather longer, 

 reaching end of peduncle of antennules, and rather wider in 

 the middle than towards extremity. General character of 

 telson as in last species, but the extremity having a central 

 small spinule, flanked on each side by a still more minute 

 spinule and pair of setse between the ultimate spines. Outer 

 uropods with seventeen to twenty-five spines on outer margin 

 of first joint. Inner uropods with smaller spines alternating 

 with larger throughout the inner margin, except between the 

 last and penultimate spines. 



Norway, Christiania Fiord and west coast {G. 0. Sars) ; 

 Lervig, Hardanger Fiord {A. 31. N.). 



Siriella norvegica has not as yet been found on our coast, 

 but may be expected to occur. Its characters are given here, 

 as well as those of the next species, for comparison with their 

 very close allies. 



Siriella crassipes, G. 0. Sars. 



? Cynthia Flemingii, H. Goodsir, Bell, British Stalk-eyed Crustacea 



1853, p. 379 (mas). 

 Siriella crassipes, G. 0. Sars, Middelhavets Mjsider, 187G, p. 89, 



pi. xxxii. 



In general characters very near the two preceding species, 

 but the whole form is somewhat more robust in proportion to 

 size, and the legs are much stronger. The following will 

 supply diagnostic characters. 



Antennules with three setai on inner margin of third joint 

 of peduncle. Antennal scale less parallel-sided than in 

 Clausii, widening slightly about the middle, as in norvegica. 

 Per^opods stout and strongly built, the joints more flattened 

 and wider in proportion to their length than in the two pre- 

 ceding species ; finger with first joint not longer in lesser 

 (front) length than broad, second joint or nail strong and well 

 curved. Telson terminating in a small spinule, flanked on 

 each side by the usual setffi, and a more minute spinule 

 between the ultimate pair of spines ; three or four basal spines 

 of lateral margin, as usual, separated by an interval from 

 following spines ; on hinder portion two to six smaller spines 

 (varying in number according to size of specimen) in the 

 intervals between the larger spines. Uropods narrow ; outer 

 with nine to twelve spines on external margin of basal joints, 

 terminal joint twice as long as broad. Inner uropods with 

 smaller spines alternating with the larger on the upper half 

 Ann. d; Maj. N. Hist. Ser. 5. Vol.x'ix. 7 



