FEOM THE GULF OF GUINEA. 31 



This species was observed in 70 tow-nettings, 29 of these were surface and 41 under- 

 surface gatherings. The under-surface comprised tow-nettings from various depths from 

 3 to 400 fathoms. 9 of the surface and 30 of the under-surface tow-nettings were collected 

 during the day, while 20 surface and 11 under-surface Avere collected during the night, 

 as shown by the formula : — 



( 9 day collections. 

 rr ff .J29 surface | 20 night ditto. 



Tow-nettmgs 70 < , , . 



i il under-surface / '^" '^^^ ^^i^to. 

 1 11 night ditto. 

 The superficial and bathymetrical distribution of BJdncalanus cormitus was co-extensive 

 with tlie area examined, except that, unlike either Eucalanus attenuatus or setiger, it was 

 not obtained in any gathering from Bauanah Creek or Loanda Harbour, where the specific 

 gravity approximates so closely to that of fresh water. I have not observed a single 

 specimen among the large number that have passed through my hands that could be 

 ascribed to Rldiicalanus gigas, Brady. 



Ehincalanus actjleatus, n. sp. (PL II. figs. 11-21.) 



Length about 3'25 mm. (exclusive of tail-setae, which were fully 1 mm. in leno-th). 

 Body ovate, attenuate towards the head. Forehead produced forward into a strongly 

 spiniform rostrum. The postero-lateral angles of the last thoi*acic segment are produced 

 backward into spine-like processes. The anterior antennae long and slender, reaching to 

 beyond the caudal stylets, 21-jointed ; the proportional lengths of the joints are nearly as 

 follows : — 



170 . 42 ■ 17 ■ 18 . 14 . 14 ■ 10 . 9 . 9 . 12 ■ 13 . 45 . 54 ■ 59 . 72 . 85 . 82 . 82 . 80 . 80 . 30 

 1 2 3 4 5 fi 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21' 



The anterior antennae are sparingly setiferous. The secondary branch of the posterior 

 antennae about two-thirds the length of the primary branch, 6-jointed, the first joint 

 fully half as long as the second, the third, fourth, and fifth small, the last as long as all 

 the preceding three together ; the end of the primary branch is furnished with four long- 

 plumose setse and a small plain one ; two plumose setas spring from the end of the last joint 

 of the secondary branch and one from each of the preceding four joints. Mandible 

 stout, the distal end with four teeth, three of which are close together and one separated 

 from the others by a deep and moderately wide sinus. I failed to observe a mandible- 

 palp. The maxilla-palp furnished with three very long sette, which are plumose from the 

 middle. The anterior foot-jaws resemble those of Hemicakmus more closely than those 

 of Hhincalanus. The posterior foot-jaw as in Hhincalanus cornutus, but differing in being 

 furnished with three ciliated heart-like processes, two of which are on the under margin 

 and near the end of the first segment and one on the upper margin of the second 

 segment. Both branches of the first four pairs of swdmming-feet 3-jointed, the second of 

 the two basal joints of the first feet is produced on the inside so as to form a stout process 

 to which the inner branch is attached. A stout curved spine springs from the end of the 

 posterior margin of the second joint of the outer branch of the second pair of swimming- 



