BIAS. 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 

 much elongated, secondary branch short and 1-jointed. 

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

 middle lobe very broad. Mandibles as in Calanus. 

 Branchial plates of the maxillae 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 Dias, but others which are 

 properly referable to distinct genera. The term Dias 

 has been generally adopted for the following species, 

 and I have therefore retained it here. 



1. DIAS LONGIEEMIS, Lilljeborg, PI. V, figs. 1- 14. 



Dias longiremis, Lilljeborg. De Crustaceis ex ordinibus tribus, 

 p. 181, tab. xxiv, figs. 113 (1853). 



Glaus. 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. 1118 (1865). 



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

 vol. xx p. 401, pi. x, figs. 16 (1857). 



