584 DR. G. H. FOWLER ON THE [June 21, 



fathoms at 6 stations of the Norske Nordhavs Expedition * ; all 

 along the West Coast of Norway up to Finrnark from 100 to 200 

 fathoms (Sars 2 ) ; in the cold area of the Faeroe Channel 

 (H.M.S. ' Eesearch,' 1896, 530 to 220 fath.). 



iii. It appears to come up to the surface from great depths at 

 night, in the Faeroe Channel (H.M.S. l Eesearch,' 1896, 

 Station 15 d) ; it has been taken off the Shetlands 3 , and in the 

 Faeroe Channel by the ' Triton ' in 1882. 



iv. It has been recorded from shallow waters round our coasts : 

 from Banff (Edwards 4 ) ; from the Forth 5 ; once, a single specimen, 

 from the Clyde (Bobertson) 6 ; oft' St. Andrews (Mclntosh) ; from 

 Valentia, where what appeared to be very young specimens of this 

 species were taken in profusion by Messrs. A. O. Walker and 

 E. T. Browne. Mr. Walker also informs me that he has received 

 specimens 5 mm. in length from off Galley Head, co. Cork. 



Now the curious fact about the specimens from Valentia, Galley 

 Head, and the Firth of Forth is that they are all very small, 

 ranging from 2 to 5 mm. : whereas in the Faeroe Channel they 

 are mostly about 7-10 mm. in length, and specimens from the 

 Norwegian North Atlantic Expedition reached the length of 

 17 mm. The length of the Banff specimens is not given. In all 

 probability the small size of the British specimens of this sub- Arctic 

 form indicates either (1) that the species attains a smaller size 

 under increased temperature ; or (2) that the larger adults are 

 oceanic, and come inshore to breed, dying or retreating again to 

 the open sea afterwards (this is Mr. Walker's suggestion) ; or (3) 

 that the small and apparently young specimens of our coasts nor- 

 mally live in the open sea but nearer the surface than the adults, 

 and are only driven on to our shores in heavy weather, or by a 

 southerly current. 



I have nothing to adduce either for or against the first suggestion. 

 Against Mr. Walker's suggestion, it may be urged that the adult 

 forms have not been recorded from inshore waters, and would 

 surely have been noticed if they arrived in great numbers to breed. 

 For, one feature of the appearance of this species on our coasts is 

 that it generally arrives in enormous numbers (Firth of Forth, 

 Banff, Yalentia in 1896 ; they were less numerous, but plentiful 

 at Valentia in 1897) : this would imply the presence at some time 

 of numerous parents, which have never been recorded. 



The third suggestion appears to me to be likely to prove the 

 correct solution ; namely, that both young and adults normally 

 inhabit open water, the young living nearer the surface and being 

 brought to our shores as occasional visitors under special circum- 

 stances of weather and current. The clue is to be found in an 



1 G. O. Sars : Norske Nordhavs Expedition, Crustacea, vol. ii. p. 37- 

 - G. O. Sars: Crustacea of Norway, vol. i. p. 11. 



3 A. M. Norman : Kep. British Association for 1868, p. 287. 



4 Edwards : Journ. Linn. Soc. ix. p. 166. 



5 Sir John Murray kindly sent me a sample of these. 



t; Robertson : Trans. N. H. SOP. Glasgow, n. s. ii. p. 69 (1890). 



