17 



defined. Last pair of legs comparatively strongly built, with the proximal 

 parts completely coalesced in the middle, terminal parts claw-like and coarsely 

 denticulated in their outer part, that on right side conspicuously larger than 

 that on left side. 



Male of somewhat smaller size than female and very unlike it in its 

 outward appearance. Anterion division regularly oblong oval in outline, with 

 the last segment quite simple, without any lateral expansions. Urosome much 

 more slender and narrow, cylindrical in form, with the 2nd segment the largest. 

 Caudal rami comparatively small and quite symmetrical, marginal setae quite 

 normally developed, none of them being spiniform. Right anterior antenna 

 very strongly hinged and somewhat resembling in structure that in male 

 Pontellidce ; proximal part of the middle section considerably tumefied and 

 composed of 4 firmly connected joints, distal part of that section formed by 

 a single elongated and highly chitinised joint movably articulated both with 

 the proximal part and with the succeeding terminal section; the latter com- 

 posed of 4 joints, the 1st of which is the largest and armed in front with a 

 long, dark-coloured claw-like spine. Last pair of legs powerfully developed 

 and very asymmetrical, the right leg being more than twice as long as the 

 left and exhibiting inside 2 differently shaped lappets, apical claw very slender 

 and abruptly curved inwards; left leg provided at the end with 2 peculiar 

 appendages, the outer one somewhat lamellar and densely ciliated outside, the 

 inner terminating in a styliform point. 



Colour of the living animal not yet ascertained. 



Length of adult female only slightly exceeding 1 mm.; that of male 

 about the same. 



Remarks. This form has been fully described and figured by the 

 present author in the above-quoted journal, and its close relationship to the 

 tropical species recorded by Scott pointed out. Indeed, after having had the 

 opportunity of examining some specimens of the latter species kindly sent to 

 me from Scott, I am now much inclined to regard it as merely a somewhat 

 depauperated form of that species left behind from a far remote period, in 

 which a considerably warmer climate and a more southern fauna prevailed in 

 our country. 



Occurrence. The present interesting form was found by Prof. H. Gran 

 very abundantly in an oyster-bed (Espevigpollen) located at Tysnes, south of 

 Bergen. It also occurred, though more sparingly, in another neighbouring bed 

 (Sel0pollen). In both these beds the water holds during the summer a very 

 high and uniform temperature amounting to no less than -f- 30 C., and also 



3 Crustacea. 





