2f) Canon A. M. Norman — Xofes on the 



Tlie antennje are furnished with three-jointed secondary- 

 branches. 



1'lie second maxillipeds and otlier mouth-organs are somc- 

 ■R-liat similar to those of Thalestris frigida. 



The first pair of thoracic feet are moderately short and 

 stout and tiie outer branches are distinctly shorter than the 

 inner ones (fig. 14) ; the spiniform seta on the outer distal 

 angle of the second basal joint is comparatively large, but the 

 spine on the inner distal angle is considerably smaller ; the 

 terminal claw of the inner branches is very long and slender 

 and the plumose seta which springs from near the middle of 

 the inner margin of the second joint is also elongated ; the 

 general structure and armature of both branches resemble 

 those of the first pair in Thalestris robu.ita, Claus, while the 

 second, third, and fouith pairs are somewhat similar to those 

 of Thalestris frigida. 



The fifth pair (fig. 15) have also a general resemblance to 

 tlie fifth pair cf that species, but the basal joint is propor- 

 tionally ratiier broader at the base, and its armature is some- 

 what diflferently arranged ; the arrangement of the armature 

 of the secondary joint is also somewhat different from that of 

 the secondary joints of the species referred to. 



The caudal furcfe are very short. 



(2) The male. — The male resembles the female, but is 

 rather smaller. The antennules have a modified structure to 

 fit them for grasping. The spine on the inner distal angle of 

 the second basal joints of the first pair of thoracic feet is 

 stiong and distinctly hooked at the end, as shown in PI. III. 

 fig. 14 a. 



The inner branches of the second pair of feet resemble 

 generally the same branches in the male of 27ialestris fn'gida, 

 but they are distinctly broader in proportion to their length, 

 and there is a slight ditference in their armature, as shown in 

 the drawing (fig. 16). 



'J'he fifth pair also resemble somewhat those of the male of 

 the species referred to, especially in their armature, but the 

 inner produced part of the basal joint is less prominent and 

 more broadly rounded and the secondary joint is rather 

 smaller (fig. 17). 



Hab. Bog Fiord; not very common. 



This Thalestris comes very near Th. frigida, and I was at 

 firi^t inclined to regard it as belonging to that species; but it 

 was icund that the difference in the structure of the first pair 

 ol thoracic feet in both the male and female and of the inner 

 biancl.es of the second fair in the male was alone sufficient to 

 distinguish it from the species referred to. The structure of 



