DIAS. 51 



Anterior antennae, in the female, 20-jointed, armed with 

 long setae, nodose, and (in the male on the right) 

 geniculated. Primary branch of the posterior antenna 

 mnch elongated, secondary branch short and 1 -jointed. 

 Labium very large, three-lobed, and setiferous, the 

 middle lobe very broad. Mandibles as in C alarms. 

 Branchial plates of the maxillse small. Anterior foot- 

 jaws largely developed and armed with many strong, 

 uncinate setae ; posterior pair provided at the base with 

 two large setiferous processes, the apical portion small. 

 The swimming feet have the internal branch of two, 

 the outer of three joints. The fifth pair of feet are 

 one-branched, those of the male prehensile. Eye 

 formed of several lenses. 



The genus Acartia of Dana includes, no doubt, not 

 only some species of Bias, but others which are 

 properly referable to distinct genera. The term Bias 

 has been generally adopted for the following species, 

 and I have therefore retained it here. 



1. Dias longieemis, Lilljeborg, PI. Y, figs. 1- 14. 



Bias longiremis, Lilljeborg. De Crastaceis ex ordinibus tribus, 

 p. 181, tab. xxiv, figs. 1—13 (1853). 



— — Claus. Die frei-lebenden Copepoden. p. 193, 



taf. xxxiii, figs. 6 — 14, and taf. iii, figs. 1 and 2 

 (1863). 



— — Boeck. Oversigt over de ved Norges Copepoder, 



p. 12 (1864). 



— — Brady. Nat. Hist. Trans. Northumberland and 



Durham, vol. i, p. 35, pi. i, fig. 14, and pi. ii, 

 figs. 11—18 (1865). 

 Calanus euchceta, Lubbock. Ann. and Mag. Nat. Hist., series 2, 

 vol. xx p. 401, pi. x, figs. 1—6 (1857). 



