FEOM THE GULF OF GULS'EA. 69 



PaRACARTIA SPINICAUDATA, 11. sp. (PL VIII. figs. 1-11.) 



Female. Length 1-25 mm. Ceplialotborax elongate, rather tumid, rounded in front, 



the postero-lateral angles of the last thoracic segment acute. Anterior antenna as long 



as the cephalothorax, 20-jointed, and hearing a number of long plumose setaj distrilnited 



as follows— one on each of the 2nd, 3ixl, 1th, 8th, 9th, 10th, 13th, 15th, IGth, and 18th 



joints, two (one smaller than the other) on the 19th, and five on the last joint. The 



7th joint is about as long as all the preceding three together ; the 12th and last joints 



are shorter than the others. The proportional lengths of the joints are nearly as in the 



annexed formula : — 



30 . 16 ■ 9 . 13 . 11 . 9 . 30 ■ 15 . 10 . 15 . 15 . 12 . 6 . 14 ■ 12 . 16 . 13 ■ 15 ■ U ■ 7 

 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20" 



Posterior antennae, mouth-organs, and first four pairs of swimming-feet as in Acartia 

 luxa, except that the last joint of the outer branch of the first swimming-feet has the 

 lower exterior surface setose. Pifth pair of feet small, 1-branched, the basal part 

 short and tumid and furnished Avith a stout curved spine, the distal half of which is 

 strongly toothed on both margins ; exteriorly and close to the spine and about a third of 

 its length is a small plain seta ; the right and left branches are alike. Abdomen short, 

 3-jointed ; tlie first segment is somewhat triangular in form and has the distal end 

 fully twice the breadth of tlie next segment ; it is also longer than both the second and 

 last segments together. Caudal stylets short and broad, rather longer than the last 

 abdominal segment, each stylet armed with a prominent and strong terminal spine and 

 two setae, one on each side of the spine ; there are also two setse on the exterior margin 

 of the stylets, and a third, Avith a distinct basal part, a little above the inner of the two 

 terminal setae. The terminal spines, which are about double the length of the stylets, 

 and all the setae, except the one last described, are plumose. 



Rubltat. Eananah Creek, Congo Eiver, in one surface tow-nettiug collected at noon 

 and in another collected at 4.30 p.m. February 7th, 1886. Several specimens, all females, 

 were obtained in these two tow-nettings. 



The more obvious characters which serve to distinguish this species are the fifth 

 feet and the peculiar form of the abdomen. 



Pakacautia dubia, n. sp. (PL VII. tigs. 41, 42 ; PL VIII. figs. 12-15.) 



Male. Length about 1-2 mm. Body elongate, broadly subtriangular in front, and 



rounded posteriorly, composed of five segments ; head indistinctly separated from the 



thorax. Anterior antennae about as long as the body, that of the left side provided with 



a number of moderately long setae, 20-jointed, the proportional lengths of the joints being 



nearly as shown in the formula : — 



16 ■ 14 ■ 6 ■ 5 ■ 5 . 8 . 10 . 10 . 12 . 11 ■ 9 ■ 20 ■ 20 . 15 . 12 . 16 . 11 . 1 8 . 10 . 8 

 ~1 2" 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18^ 19 20" 



The proximal half of the right antenna, which bears several long plumose hairs, 

 has the lower portion somewhat dilated ; there is a hinged articulation between the fifth 



