of the Fishery Board for Scotland. 235 



DESCRIPTION OF SPECIES. 



CRUSTACEA. 



1. COPEPODA. 



Family Calanid^. 

 Genus Paracalanus, Boeck (1864). 



Paracalanus parvus (Claus). 



1863. Calanus parvus, Claus (13),* p. 173, pi, xxvi. figs. 

 10-14; pi. xxvii. figs. 1-4. 



1864. Paracalanus parvus, Boeck (5), p. 232. 



1892. Paracalanus parvus, Canu (11), p. 169. 



1893. Paracalanus parvus, I. C. Thompson (33), p. 7, pi. xv. 

 fig. 5. 



1894. Paracalanus parvus, T. Scott (30), p. 26, pi. i. figs. 1-19. 



Habitat. — East of May Island, in a surface tow-net gathering. Frequent. 

 Off St Monans. Not common. 



Paracalanus parvus is easily distinguished from any other species of 

 the British Calanidse by the structure of the fifth pair of thoracic 

 feet in both sexes. The only other British record for this species seems 

 to be that of I. C. Thompson in the ' Copepoda of Liverpool Bay.' The 

 distribution of the species appears to be world-wide ; it has been re- 

 corded from the North Sea, from the Atlantic (North and South), from 

 the Mediterranean, and from the China Sea. 



Genus Acartia, Dana, 1846. 



Acartia clausi, Giesbrecht. 



1889. Acartia clausi, Giesbrecht (17), p. 332. 



1890. Acartia clausi, Canu, (10a), p. 326, pi. xxiv. 



1893. Acartia clausi, I. C. Thompson (33), p. 8, pi. xv. fig. 6. 



1894. Acartia clausi, T. Scott (30), p. 67, pi. vii. figs. 33-40. ' 



Habitat, — Several parts of the Forth area. One of the chief characters 

 that distinguish this species is the form of the fifth pair of thoracic feet. 

 The fifth pair in the female are each armed with a stout and compara- 

 tively short apical spine in addition to the plumose seta. The following 

 forms of Acartia are also obtained in the Firth of Forth, viz. : — Acartia 

 longiremis (Lillj.), generally distributed, especially in the estuary proper. 

 Acartia discaudata, Giesbrecht, off Musselburgh. Acartia bijilosus, Gies- 

 brecht, West of Queensferry. 



Family Pseudocyclopiid^e, nov. family. 



Body comparatively robust. Anterior antennae short, sixteen to 

 seventeen-jointed. Alike on both sides in the male, and similar to those 

 of the female. Mouth organs and swimming-feet like those of the 

 Calanidai. Fifth pair in the female simple, one-branched, and two-jointed ; 



* The numbers in parentheses correspond with the numbers in the Bibliographical 

 list at the end of the paper. 



