492 



occurs a rather strong spinule. Colour somewhat variable, now uniformly 

 olive-green, now yellowish variegated with brownish patches. Length of 

 adult female reaching 38 mm. 



Benwrli). — As recently pointed out by the Rev. Mr. Stebbing, this 

 form was first recorded by J. C. Fabricius under the name of Gammarus 

 homari, it being stated to partly constitute the food of the common lobster. 

 It was somewhat later described by 0. Fabricius under another name, viz., 

 Gammanis arenaritis. The Gammarus Sabini of Leach is the same species, 

 and under this specific name it has generally been recorded by the several 

 authors. It is a magnificent and easily recognizable form, well distinguished 

 both by its comparatively large size, and by the sti'ongly-carinated and 

 spinous back. 



Occurrence — The species occurs along the whole coast of Norway, 

 from the Christianiafjord to Vadso, in comparatively shallow water among 

 algae; but seems to attain a much fuller development in the arctic region 

 than in more southern latitiides. 



Distributmn. — G-reenland (Fabr.), Spitsbergen (Goes), the Murman 

 Coast (Jarzynsky), arctic America (Stimpson), British Isles (Sp. Bate), 

 Kattegat (Meinert), coast of France (Chevreux). 



6. Amathilla angulosa (Rathke). 



(PL 173, fig. 2). 

 Gammarus angulostis, Eathke, Acta Acad. Leopold. T. XX, p. 72, PI. Ill, fig. 3. 



Body short and stout, with the back distinctly carinated, the carina 

 being, however, but very little elevated, forming no distinct dorsal project- 

 ions. First segment of urosome with a saddle-like depression dorsally, and 

 slightly carinated behind this. Cephalon nearly as long as the first 2 

 segments of mesosorae combined, lateral corners evenly rounded. Coxal 

 plates nearly as in the type species, except that the 5th pair have the 

 posterior lobe deeper than the anterior. Last pair of epimeral plates of 

 metasome obtusely angular at the lateral corners. Eyes oblong in form, 

 with dark brown pigment. Antennae comparatively shorter and stouter than 

 in A. homari, and nearly equal in length, accessory appendage of the superior 

 ones composed of only 4 articulations. Gnathopoda exactly alike botli in 

 size and structure, otherwise resembling those in the type species. Pereiopoda 

 short and stout, the posterior pairs being scarcely more elongated than the 

 anterior, basal joint of last pair oval in form, with the posterior edge evenly 



