125 

 Gen. 33. DaCtylOpUSla, Norman, 1903. 



Syn : Nauplius, Philippi (not Miillev). 

 Dactylopus, Claus (not Gill). 



Generic Characters. Body, as a rule, rather stout, tapering behind, with the 

 anterior division more or less depressed and generally not sharply marked off from 

 the posterior. Cephalic segment large, but not very deep, rostrum well defined at 

 the base. Urosome with none of the segments expanded laterally; caudal rami 

 short. Anterior antenna) comparatively short, with a somewhat varying number 

 of joints. Posterior antennae with the proximal joint not divided in the middle, 

 outer ramus composed of 3 well-defined joints. Oral parts normal. 1st pair of 

 legs with the outer ramus generally much shorter and stouter than the inner, 

 terminal joint lamellar and armed with 4 strong outward-curving claws and a 

 slender seta inside the latter; inner ramus distinctly 3-articulate, with the outer 

 2 joints quite short, the last carrying 2 strong claws. Natatory legs well deve- 

 loped, with the rami rather broad, the inner one somewhat shorter than the outer 

 and having 2 setffi inside the middle joint; inner ramus of 2nd pair of legs in 

 male conspicuously transformed, biarticulate, with a strong spine outside the distal 

 joint. Last pair of legs in female with both joints generally broad and lamellar ; 

 those of male, as usual, much smaller. 



Remarks. This genus was established as early as the year 1840 by 

 Philippi ; but the name he applied to the genus, Nauplius, cannot properly be 

 accepted, since it was used by 0. Fr. Midler in a very different sense, and at 

 present is in general use to distinguish the well-known earliest larval stage of lower 

 Crustacea. Nor can the generic name proposed by Claus, Dactylopus, be employed, 

 as it was appropriated some years previously by Gill for a genus of fishes. For 

 this reason, the Rev. A. M. Norman has recently proposed the change of the Clausian 

 name to Dactylopusia. 1 ) The genus was taken by Claus in a much wider sense 

 than here adopted, and Boeck had already called attention to the fact that some of 

 the Clausian species of Dactylopus ought to be separated generically. Still, how- 

 ever, recent British authors refer to this genus forms, which, by the presence of 

 2 ovisacs, clearly show themselves to belong to quite a different family, viz., the 

 Diosacehlir, to be treated of farther on. Even in the restriction here adopted, 

 this genus seems to comprise a great number of species from different parts of 

 the oceans. To the Norwegian fauna belong at least 5 well-defined species, to 

 be described below. 



') Should perhaps more properly have been Dacti/lopodia. 

 17 Crustacea. 



