66 ME. T. SCOTT ON ENTOMOSTEACA 



long. 6° 25' 8" E.), 20 fathoms, January 23rd (day collection). Station 22, 20 fathoms, 

 February 4th (day collection). Lat. 5° 55' 1" S., long. 11° 30' 7" E., surface, Eebruary 

 18th (night collection), &c. 



Acartia laxa was observed in 38 tow-nettings, 11 of which were surface and 27 under- 

 surface gatherings. The under-surface tow-nettings ranged in depth from 5 to 235 fathoms. 

 Eour of the surface and 19 of the under-surface gatherings were collected during the day, 

 while 7 surface and 8 u.nder- surface gatherings were collected during the night, as 

 shown in the formula : — 



f 4 day collections. 



11 surface \ ^ -^^^ ^^^^0. 



Tow-ncttin2:s- 38 ^ , "^ . 



27 under-surface \ ^^ "^^^ ^^^"0. 

 J- 8 night ditto. 



Acartia laxa was of frequent occurrence in nearly all of the tow-nettings in which it 

 was observed. 



AcAiiTiA DENTICORNIS, Brady. 



1883. Acartia denticornis, Brady, op. cit. j). 73, pi. xsxi. fig. 1, pi. xxxii. figs. 12-17. 



Habitat. Lagoon, Sao Thome Island, surface tow-netting, January 27th (night col- 

 lection). Libreville, Gaboon River, surface, January 28th (day collection). Lat. 4° 40' 

 S., long. 10° 25' 2" E., surface, Eebruary 5th (night collection). Bananah Creek, Congo 

 Ptiver, surface, Eebruary 7th (day collection). Loanda Harbour, surface, Eebruary 13tli 

 (day collection). 



The distribution of Acat'tia denticornis within the area dealt with in this Report appears 

 to have been more restricted than Acartia laxa ; it was also more confined to inshore and 

 surface gatherings than was that species. It is interesting to note that this apparent 

 preference of A. denticornis for localities more or less inshore is borne out to some extent 

 by the ' Challenger ' records, where the following statement occurs (loc. cit. p. 74) : — 

 " Abundant in Hilo Harbour, Sandwich Islands (August 1875) ; one or two specimens 

 noted in a gathering from the Philippine Islands and (?) in the Atlantic, north of Tristan 

 d'Acunha." 



Acartia denticornis was obtained in 14 of the ' Buccaneer ' tow-nettings — all of them 

 surface gatherings. Eight of the tow-nettings were day and 6 were night collections. 

 The specific gravity of the water in which it occurred varied from 1*0255 to 1-0087. 



ACABTIA PLUMOSA, u. sp. (PI. VII. figs. 22-32.) 



Length 1'2 mm. Body elongate-ovate, somewhat rounded in front; the rounded 



postero- lateral angles of the last thoracic segment bear a number of small spines. 



Anterior antennae about as long as the cephalothorax, those of the female 20-jointed and 



furnished witli numerous plumose setae ; the annexed formula shows the proportional 



lengths of the joints ; — 



18 ■ 11 . lU ■ U . 12 . 8 . 8 ■ 5 . 13 . 11 . 15 ■ 15 . 1.5 ■ ]2 . 14 ■ 15 ■ 10 ■ 18 ■ 10 ■ 8 

 1 2 3 4 5 6 7 8 y 10 11 12 13 14 15 It) 17 18 19 2o' 



