X. fallax. A 3rd Norwegian species has been described in the present work 

 as X. propinqvus. The most reliable character for distinguishing the species 

 of the present genus is unquestionably the structure of the last pair of legs. 



1. Xanthocalanus minor, Giesbr. 



(PL I). 



Xanthocalanus minor, Giesbrecht, Fauna und Flora des Golfes von Neapel: Pelagische Cope- 

 poden, p. 286 (footnote), PI. 12, Fig. 32. 



Specific Characters. Female. Body moderately slender, with the 

 anterior division oblong oval in form, greatest width not nearly attaining half 

 the length and occurring somewhat behind the middle; dorsal face only slightly 

 vaulted. Cephalosome nearly as long as the exposed part of the trunk, and 

 exhibiting behind the middle dorsally a distinct transverse suture; anterior 

 extremity narrowly rounded. Rostral filaments of moderate length and abruptly 

 reflexed. Last trunkal segment completely coalesced with the preceding one; 

 lateral lobes triangularly produced, and extending somewhat beyond the middle 

 of the genital segment. Urosome comparatively short, scarcely exceeding in 

 length 1 /4 of the anterior division; genital segment only slightly protuberant 

 below, and about the length of the 2 succeeding segments combined; anal 

 segment very small. Caudal jami scarcely longer than they are broad; apical 

 setae well developed and somewhat divergent, the innermost but one, as usual, 

 considerably longer than the others. Anterior antennae rather elongated, ex- 

 tending, when reflexed, to the end of the caudal rami. Posterior antennae 

 and oral parts almost exactly as in X. fallax. Natatory legs likewise of a very 

 similar structure, though having the spinules of the inner ramus fewer in number. 

 Last pair of legs, however, rather unlike those in the said species, the outer 

 2 joints being, as in X. borealis, completely coalesced to an elongated some- 

 what curved piece armed at the end with only 3 comparatively short, subequal 

 spines, edges of the piece nearly smooth, with only a few cilia at the outer 

 curvature. 



Body in the living animal highly pellucid, with only a faint rosy pig- 

 ment at the end of some of the segments. 



Length of adult female reaching to 2.70 mm. 



Remarks. The figure given by Giesbrecht of the last pair of leg in 

 his X. minor agrees pretty well with those appendages in the above-described 

 form, and I think therefore that I am right in identifying both, though no other 

 figures were given by Giesbrecht, nor any description of the species, The 



