REPOET ON A COLLECTION OF ANTARCTIC PLANKTON. 295 



occurred in only one haul. It also is a common northern 

 form, and I recently found it plentiful in material collected 

 by Dr. G. H. Fowler, in H.M.S. "Kesearch," off the 

 Faroe Islands. It occurs about our British and French 

 shores in fair numbers. 



The two remaining species, Oithona spinifrons and 

 Ectinosomaatlanticum, have a wide distribution, especially 

 in northern latitudes. Both were sparingly distributed 

 in this collection. 



Paracartia antarctica, n. sp. PL XVIII. , 

 figs. 1—12. 



Length (exclusive of tail setae) 1*75 mm. Male rather 

 smaller and more slender than the female. The female 

 is conspicuous by the acute lateral angles of the last 

 thoracic segment of the cephalothorax. Anterior antennas 

 rather shorter than the cephalothorax, 20-jointed in the 

 female (fig. 3) and 11 in the right male antenna (fig. 2). 

 The ninth joint in the latter is finely serrated on the 

 under surface, a geniculation occurring between the 9th 

 and 10th joints. 



Posterior antennae and mouth organs similar to those 

 of P. spinicaudata, Scott. Outer branch of four first pair 

 of swimming feet 3-jointed, the division between the two 

 terminal joints in first pair (fig. 9) being almost imper- 

 ceptible. Inner branch 2-jointed. Fifth pair of feet in 

 female (fig. 12) 1-branched, each branch 2-jointed. Basal 

 joint somewhat quadrangular, and terminating on the 

 posteroir inner side, with a strong lanceolate spine. 

 Terminal joint bifurcates at apex forming two spines, with 

 a small seta on inner side of outer one. 



The fifth pair in the male (fig. 11) is large and conspicu- 

 ous, forming a strong clasping organ. The right foot has 

 two broad basal joints, terminating in a long sickle-shaped, 



