Gen. 17. ParRStephOS, G-. 0. Sars, n. 



Generic Characters. Form of body more slender than in Stephos, with 

 the anterior division less tumefied and the urosome more elongated. Front 

 blunt below, as in Stephos. Antennae about as in that genus. Oral parts 

 likewise of a very similar structure, except that the masticatory part of the 

 mandibles is considerably more expanded, with the outermost cutting-tooth very 

 large and claw-like. Natatory legs not particularly powerful, some of them (in 

 male) peculiarly transformed. Last pair of legs in male largely developed and 

 very asymmetrical, right leg slender and terminating in a strong denticulated 

 claw, left leg much coarser, with the antepenultimate joint the largest. 



Remarks. This new genus is founded upon a solitary male specimen, 

 which, though evidently referable to the present family, exhibits so many essential 

 differences from the males of the genus Stephos, that it cannot properly be included 

 in that genus. It is very probable, that also the female, when found, will exhibit 

 some peculiarities, at least in the structure of the last pair of legs. 



27. Parastephos pallidus, G. 0. Sars, n. sp. 



(PI. XLIV). 



Specific Characters. Male. Anterior division of body, seen dorsally, 

 oblong oval in form, greatest width not attaining half the length, anterior extremity 

 narrowly rounded, posterior less attenuated; seen laterally, moderately vaulted 

 above, with the dorsal margin forming a perfectly even curve as far as the blunt 

 rostral part. Last segment of metasome with the lateral parts but slightly pro- 

 duced and narrowly rounded at the tip. Urosome comparatively slender, con- 

 siderably exceeding half the length of the anterior division, last segment well 

 developed. Caudal rami somewhat longer than they are broad, and not at all 

 divergent; apical setae about as in Stephos. Eye, as in that genus, wholly absent. 

 Anterior antennae, when reflexed, reaching about to the end of the 3rd caudal 

 segment, structure exactly as in Stephos. Posterior antennae with the outer ramus 

 considerably longer than the inner. Outer ramus of right 2nd leg peculiarly trans- 

 formed, being quite short, not even attaining the length of the inner ramus, and 

 composed of only 2 joints, the proximal one simple, the distal one carrying at 

 the tip 4 natatory setae and a single spine outside them. Inner ramus of right, 

 4th leg much larger than that of the left, middle joint considerably dilated, 



10 Crustacea. 



