new to or rare in the British Seas. 99 



joint of peduncle of antennales, I may mention that in some 

 specimens of 8. crassipes I liave not been able to make out 

 more than two, and in one specimen of 8. Brooki the left 

 antennule has a second seta, while the right bears as usual 

 one. 



8. Brooki has been found at Tarbert, Loch Fyne, by the 

 Fishery Board, in company sometimes with 8. Clausii. I 

 have named the species after Mr. G. Brook. 



8irieUa armata (M.-Edw.) . 



Cynthia armata, M.-Edw. Hist. Nat. d. Crust, ii. p. 463 (mas, Jide Q. 



O. Sars). 

 Mysis Oriffithsiat, Bell, Hist. Brit. Crust, p. 342. 

 Mysis rustratm, Guerin, Iconog. Crust, pi. xxiii. fi.^. 3 (probably). 

 Siriella armata, G. O. Sai-s, Middelhavets Mysider, 1876, p. 96, pi. xxxv. 



Animal very long and slender. Rostrum of great size, the 

 extremity very acute and reaching the end of the second 

 joint of the peduncle of the antennules. Antennal scale long 

 and narrow, not quite so long as peduncle of antennules. 

 Per^opods slender. Telson terminating usually in four equal- 

 sized spinules and two seta3 between the ultimate spines. 

 Wide intervals between the larger spines of lateral margin, 

 these intervals occupied by six to ten smaller crowded spines 

 of nearly equal size. Uropods very long and unusually 

 narrow ; outer bearing very numerous (twenty-five to thirty) 

 spines on external margin, second joint about one third to one 

 half longer than broad. Inner margin of inner uropods with 

 numerous spines, gradually increasing in length distally, and 

 without admixture of smaller spines. Length f inch, or 20 

 millim. The branchial appendage (?) of the second and 

 following pleopods in the male is completely coiled. 



The greatly developed rostrum at once distinguishes this 

 species from the other British representatives of the genus ; 

 but another form from the Mediterranean, Siriella frontalis, 

 M.-Edw., bears a close general resemblance, but the bran- 

 chial appendages of the pleopods of male are wholly different 

 and not coiled, and on this ground Glaus has instituted a wqw 

 genus — Pseudosiriella — for its reception *. There are three 

 spinules at the termination of the telson in this species, and 

 as many as fifteen smaller spines are in the intervals between 

 the larger spines on the sides of the telson. 



* Pseudosiriella frontalis, M.-Edw., is also a member of the British 

 fauna. 1 have a drawing made many years ago, at a time wheu I had no 

 other Crustacea than British, which imdoubtedly represents the t'emale 

 of this species ; but unfortunately no locality is under the drawing. The 

 specimen was probably one sent to me for examination. 



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