377 



Page 141. 

 Westwoodia assimilis, G. 0. Sars. 



Distribution. Polar Islands north of Grinnell Land (2nd Fram Exp.). 



Page 144. 

 Add the following species: 



Westwoodia monensis (Brady). 



(Suppl. PJ. 15). 



Pseudothakstris monensis, Brady. On Copepoda and other Crustacea taken in Ireland and the 

 North east coast of England. Trans. Nat. Hist. Soc. N. D. & N. C., Vol. XIV, p. 59, PI. 1, 



figs. 15, 16. PI. JIF, figs. 11 16. 



Specific Characters. Female. Body of the usual short pyriforra shape, 

 with the anterior division much dilated, the posterior short and tapered. Cephalic 

 segment large, but not nearly so deep as in W. minuta; the 3 succeeding seg- 

 ments less conspicuously imbricate. Eye of quite normal structure. Anterior 

 antennae very slender, tapering, and composed of 8 well defined joints, 4 of which 

 belong to the terminal part. Posterior antennae and oral parts scarcely different 

 in structure from those in the said species. 1st pair of legs likewise very similar, 

 the outer ramus being distinctly biarticulate and about half as long as the 1st 

 joint of the inner, seta attached inside this joint comparatively small and more 

 remote from the base; apical claws of same ramus comparatively shorter than 

 in IF. minuta and still more unequal in size. Natatory legs scarcely different 

 in structure from those in W. minuta. Last pair of legs with the distal joint 

 rather small, oblong oval in form, outermost marginal seta somewhat remote 

 from the base, middle one very thin, hair-like; inner expansion of proximal joint 

 comparatively broader than in W. minuta and scarcely extending beyond the 

 distal joint. 



Male differing from the female in a manner similar to that found in the 

 other species of the present genus. Inner ramus of 2nd pair of legs biarticulate, 

 with 2 subequal spines at the tip, both slightly curved outwards. Last pair of 

 legs not much different in shape from those in female; inner expansion of proximal 

 joint however comparatively smaller and only provided with 3 marginal setae. 



Colour yellowish grey. 



Length of adult female 0.55 mm. 



Remarks. The above described form is unquestionably that recorded 

 by Prof. Brady as Pseudothalestris monensis. It is closely allied to the species 



50 Crustacea. 



