52 G. 0. SARS. CRUSTACEA. [norw. pol. exp. 



carrying 2 small tentacular filaments. Last pedigerous segment wholly 

 coalesced with the penultimate one, and, in female, having the lateral parts 

 lamellarly produced. Tail slender and elongated, composed in female of 4, 

 in male of 5 segments, the last in both sexes extremely small. Caudal rami 

 lamellar, with 4 apical setae. Anterior antennae in female 24-articulate, in 

 male more slender, and clothed in their proximal part with well-developed 

 sensory appendages. Posterior antennae with the outer ramus much longer 

 than the inner. Mandibles slender, with the 2 outer cutting teeth strong, 

 bidentate at the tip, the others setiform; palp with the outer ramus compa- 

 ratively small. Maxillae with the masticatory lobe very large; vibratory 

 lamella, on the other hand, poorly developed. Anterior maxillipeds rather 

 strong, anterior lobes densely crowded together, and carrying comparatively 

 short setae, the outermost of which are claw-like, apical appendages scarcely 

 transformed. Posterior maxillipeds exceedingly slender, with the terminal 

 part reflexed and only sparingly setiferous. Oral parts in male not trans- 

 formed. Natatory legs powerfully developed, posterior face smooth, inner 

 ramus of the 2 anterior pairs uniarticulate, of the 2 posterior biarticulate. 

 Last pair of legs in female 3-articulate, terminal joint slender, sub-spatulate, 

 terminating in a number of short digitiform spines; those in male exceed- 

 ingly large and complex in structure, with both legs largely developed, the 

 left one with a long, styliform inner ramus. 



Bemarks. This new genus is only provisionally placed within the family 

 ScolecithricidcB. It differs, indeed, in the character upon which this family 

 has chiefly been founded, the apical setae of the anterior maxillipeds being 

 scarcely transformed at all; but in other characters it seems to approach 

 nearer to the forms included in this family than to those of other Calanoid 

 families. The genus comprises as yet only a single species, to be described 

 below. 



6. Undinella ohlonga, n. sp. 

 (PI. XII, XIII). 



Specific Characters. Form of body rather slender, especially in the 

 male. Anterior division regularly oblong oval in form, obtusely rounded in 

 front, deeply emarginated behind. Cephalic segment defined behind by a 

 distinct transversal suture, rostral prominence very conspicuous, pointing 



