54 



7. Diastylis Goodsiri (Bell) 



(PI. XLI.) 



Alauna Goodsiri, Bell, in Belcher's Last of the Ai'ctic Voyages, Vol. II, p. 403, 



PI. XXXIV, fig. 3. 



Syn: Diastylis plumosa, M. Sars. 



Specific. Characters. Female. Body of very robust form, and thickly 

 covered all over with short plumose hairs, anterior division considerably tumefied 

 and broadly oval in form, with the dorsal face boldly arched. Carapace large 

 and deep, fully twice as long as the exposed part of the trunk, and greatly 

 vaulted above, surface without any spines or denticles; pseudorostral projection 

 rather produced, conical, horizontal, subrostral corners obsolete. Last pedigerous 

 segment with the lateral parts scarcely produced behind. Tail (exclusive of the 

 terminal appendages) somewhat shorter than the anterior division, lateral corners 

 of the 5 anterior segments much produced, spiniform. Eye inconspicuous. Sup- 

 erior antennae with the 1st joint of the peduncle very large, much longer than 

 the other 2 combined, and clothed at the tip with numerous long plumose setae, 

 last joint shorter than the 2nd. Inferior antenme with the terminal joint un- 

 usually large, conically produced, apical seta very much elongated. First pair of 

 legs scarcely longer than the carapace, basal joint almost attaining the length of 

 the remaining part of the leg, and spinulose in its distal part, being moreover 

 fringed with numerous long plumose setae, the last 3 joints not very different 

 in length ; 2nd pair with the basal joint rather large and curved, being minutely 

 denticulate outside, and fringed along the lower edge with a dense row of long 

 plumose set&3, antepenultimate joint longer than the last 2 combined; 3rd and 

 4th pairs comparatively strongly built and densely setiferous, basal joint partly 

 denticulate. Uropoda with the rami subequal in length, and about half as long 

 as the stem, inner ramus mucronate, with the joints imperfectly defined, spinules 

 of the inner edge about 12 in number and, like those of the stem, unusually 

 slender, setiform. Telson rather produced, reaching as far as the stem of the 

 uropoda, proximal thickened part comparatively short, distal part armed on each 

 side with numerous slender, setiform spinules, amounting to 20 in all, apical 

 spinules very small. Colour whitish. Length about 25 mm. 



Remarks. This form was first recorded by Bell from the polar islands 

 of America as Alauna Goodsiri, and was some years afterwards found off the 

 Finmark coast by my late father, who regarded it as new, and described it 

 briefly under the name of Diastylis plumosa. It is by far the largest of all 



