THE MEDirS^. 



183 



It is obvious that of the five epiplanktou zones studied, this species was most plentiful 

 in number and most frequently captured at 100 fathoms. 



Unlike the previous species, it also occurred in eight closing-nets. This number is 

 not large, out of a total of 37 such nets, but sufficiently large to suggest that the species 

 was really alive at some considerable depth, and that the captures, at any rate in the 

 upper mesoplankton, were not merely of dead specimens sinking to the bottom ; in the 

 lower zones they may have been so, as this was the commonest epiplankton species. 



The following table shows a sudden drop below 500-400 fathoms in the average 

 number of specimens captured per 100 fathoms traversed : — 



This drop may indicate approximately the break between living and dead specimens ; 

 and in this connection it is interesting to compare the observations on the same species 

 in the Fseroe Channel (Proc. Zool. Soc. 1898, p. 1023). I have also added a similar 

 comparison of the distribution of Aglantha digitalis in the Paeroe Channel with the six 

 specimens from the Bay of Biscay which Mr. Browne thinks may perhaps be referable 

 to this species (p. 176 above). 



It may be only a coincidence that rosea failed below a temperature of 46°-4<8° in the 

 Faeroe Channel, and that beloAV 49°-50° the average specimens per 100 fathoms 



* Actual numbers captured. 

 SECOND SERIES. — ZOOLOGY, VOL. X. 



31 



