NOTES ON THE DISTRIBUTION OF AMPHIPODA. 179 



Now as to the second question, viz., the proportion of 

 species at different depths, I find on taking out all the 

 species of Sars of which the depth at which they occur 

 is given (but omitting pelagic and parasitic species) the 

 results shown in the annexed summary. 



And, as it is impossible for species to be taken at a 

 greater depth than the dredge has gone, while it is not 

 only possible, but very probable, that the dredge will 

 catch some specimens between the bottom and the 

 surface while being hauled up, it is more likely that 

 species will be recorded at too great a depth than the 

 reverse. 



Where a range of depth is given I have taken the 

 mean, e.g., 20 to 100 fath. is reckoned as 60 fath. 



The following L.M.B.C. species have not yet been 

 found in Norwegian waters, those marked " M." being 

 Mediterranean species : 



Lysianax longicornis (Lucas). M. 



Socarnes erythrophthalmus, Eobertson. 



Nannonyx spinimanus, Walker. 



Phoxocephalus fultoni, Scott. M. 



Amphilochus melanops, Walker. 



Gyproidea brevirostris, Scott. 



Syrrhoe fimbriatus, Stebbing and Eobertson. 



Guemea coalita (Norman). 



Mcera batei, Norman. 



Leptocheirus pilosus, Zaddach. M. 



Photis pollex, Walker. 



Podocerus ocius, Bate. M. 



P. cumbrensis, Stebbing and Eobertson. 



Unciola crenatipalmata (Bate). 



Colomastix pusilla, Grube. M. 



The following is a summary of the depths at which the 



