FEOM THE GULF OF GUINEA. 



9 



The following Table exhibits some points of interest respecting the general distribution 

 of species in surface and uuder-suri'ace, and in day and niglit, collections: — 



Table I. — Description of the Tow-net Gatherings. 



It will be observed from this Table that the difference between the average number of 

 species in each of the day and night surface tow-net gatherings is rather considerable; 

 while as regards the average number of species in each of the day and night under-surface 

 tow-net gatherings there is comparatively little difference, and the difference shoAvn is 

 the reverse of that observed in the surface tow-net gatherings. Further, the average 

 number of species in the surface-gatherings is much greater in those collected during 

 the night, but in the under-surface gatherings the average is rather greater in those 

 collected during the day ; while in the combined surface and under-suxface tow-nettings 

 the average is, again, in favour of the night collections. 



The area in which the tow-net gatherings were made may be described approximately 

 as extending from lat. 7° 54' N., long. 17° 25 W., eastward to Accra on the Golb Coast, 

 thence southwards across the Bights of Benin and Biapra to Slo Thome Island ; 

 from Sag Thome Island eastwards towards the mouth of the Gaboon River ; then 

 southwards to the mouth of the Congo and to Bananah Creek, and thence to 

 LoANDA Harbour. No gatherings from mid-ocean are included in the collection : the 

 greatest distance from land where tow-nettings were collected was not much, if at all, 

 over 400 miles ; but the greater number of them were collected much nearer land than 

 that, and this probably explains why the ' Buccaneer ' Copepoda — which exceed in number 

 of species those obtained from the ' Challenger ' collections, extending over an immensely 

 wider area — differ so much in the entire absence of some species, and in the com 

 paratively greater abundance of others, when compared with the ' Challenger ' Copepoda, 

 and also accoixnts for the presence of many curious and interesting species not repre- 

 sented in that collection. 



second series. — ZOOLOGY, VOL. VI. 2 



