201 



Trondhjemsfjord. As a rule, it occurs together with ,SY. in/laf/i*, but 

 in one place on the Trondhjemsfjord, at Rodbjerget, I found it unmingled 

 with the former, and in great abundance among the roots of 

 prolifera. 



Gen. 2. StegOCephaloideS, G-. 0. Sars, n. 

 Syn: Stegocephalus, Boeck (part). 



Body still more robust and compact than in the preceding genus, 

 with boldly curved back, which is nearly perpendicularly denexed in front. 

 Cephalon and coxal plates about as in that genus, though the 4th pair of 

 the latter are still larger, and have the distal edge angularly bent. Eyes 

 wanting. Antennae comparatively short, and subequal in length, the superior 

 ones, however, much stronger than the inferior, with the peduncle somewhat 

 flattened, -and the flagellum only composed of 4 articulations, the 1st of 

 which is very large, and densely clothed with fascicles of sensory bristles, 

 the last very narrow, spiniform. Oral parts scarcely differing essentially 

 from those in StegocepJialus. Gnathopoda subequal, both as to size and struc- 

 ture, propodos in both oblong, tapering distally, dactylus very short. Pen- 

 ultimate pair of pereiopoda of same structure as the antepenultimate ones, 

 the basal joint being in both narrow linear, not laminarly expanded. Last 

 pair of pereiopoda considerably shorter than the preceding pairs, and having 

 the basal joint very large and laminar, forming inferiorly a denexed angular 

 lobe. Uropoda and telson about as in StegocepJialus, though the last pair of 

 the former have the rami quite naked. 



Remarks. - - The value of this new genus may perhaps be questioned, 

 since there is no essential difference to be found in the structure of the oral 

 parts from those in the genus Stegocephalus. I have, however, found it 

 convenient to establish this genus, as there are at least 2 species which show 

 the very same essential differences from StegocepJialus. These differences 

 chiefly consist in a somewhat different structure of the superior antennae, 

 the subequal gnathopoda, and the different aspect of the penultimate pair of 

 pereiopoda, the basal joint of which is not laminarly expanded but narrow 

 linear, as with the antepenultimate pair. The genus comprises, as yet, 

 distinct species, to be described in the sequel. 



26 Crustacea. 



