62 



19. Orchomene serratus, JBoeck. 



(PI. 23, fig. 1). 

 Orchomene serratus, Boeck, Crust. Ampbip. bor & arctica, p. 35. 



Body comparatively robust, with broadly vaulted back. Lateral 

 corners of cephalon considerably projecting and obtusely rounded at the tip, 

 in male much narrower than in female. Coxal plates rather large, the 4 

 anterior pairs more than twice as deep as the body, 5th pair about as deep 

 as broad. Last pair of epimeral plates of metasome nearly right-angled, 

 posterior edge straight and very coarsely serrated, number of serrations 

 16 20. First segment of urosome transversally impressed at the base and 

 having behind an evenly rounded dorsal carina. Eyes narrow oval, tapering 

 above, pigment dark brown, with a somewhat lighter reddish coating. An- 

 tennae about as in Batei. Epistomal plate very like that in the latter 

 species, but somewhat broader and less projecting. Anterior gnathopoda less 

 robust than in the said species, propodos fully as long as the carpal and 

 meral joints combined and nearly of uniform breadth throughout. Basal joint 

 of the 3 posterior pairs of pereiopoda fully as long as the remainder part 

 of the leg. Last pair of uropoda in female with the inner ramus shorter 

 than the basal joint of the outer and armed on the inner edge with 3 dent- 

 icles. Telson broadly ovate, tapering distally, with 3 pairs of dorsal 

 denticles, cleft very narrow and extending to about the middle of the telson. 

 Colour more or less yellowish or ochraceous, with dark brown intestine. 

 Length of adult female 10 mm. 



Remarks. - This form, confounded by Boeck with the preceding species, 

 may be easily known from the latter by its much more plumpy body., the 

 narrower lateral corners of -the cephalon, the more slender anterior gnatho- 

 poda, but especially by the. very coarse serrations of the last pair of epimeral 

 plates of the metasome. It also attains a considerably larger size than that 

 species. 



Occurrence. - The species would seem to occur along the whole coast 

 of Norway up to Finmark in moderately deep water, from 30 to 100 fathoms. 

 Boeck collected it at Skudesnaes and Lyngholmen, the latter locality lying 

 in the outer part of the Hardangerfjord. 



Distribution. The Norse Island, Spitsbergen (collected on the Nor- 

 wegian North Atlantic Expedition) ; the Siberian Polar Sea (Stuxberg). 



