(Holmes, 1903)
Description:
Coxal plate 2 short and rather angular, posterior angle prolonged especially in male; coxal plate 5 anterior lobe very elongate. Epimeral plate 3 posterodistal angle with minute tooth.
Head, lateral lobe small, angular; eyes moderately large and rounded. Antenna 1 article 3 almost as long as 2, flagellar articles poorly defined, peduncle and flagellum with numerous long setae on posterior margin; accessory flagellum very small. Antenna 2 only little longer than 1, especially robust in male, peduncle article 5 longer than 4, flagellum very short, robust, flagellar articles poorly defined, flagellum and peduncle article 5 often with dense tufts of short setae. Gnathopod 1 propodus oval, narrowing distally, palm strongly oblique, straight, delimited by 2-3 small spines, dactylus with inner margin serrate. Female gnathopod 2 much larger than 1, basis with several long setae on anterior margin, propodus large and oval, palm delimited by 2-3 small spines, palmar margin concave with large angular distal process. Male gnathopod 2 very large, basis short with several long setae on anterior margin, propodus oval in small specimens with small proximal process, in larger specimens propodus elongate with enormous proximal process. Pereopods 3-4 basis, anterior margin with long setae, merus broad with numerous long setae, anterodistal angle produced and overlapping small carpus. Pereopod 5 basis expanded. Pereopods 6-7 robust, basis moderately expanded, posterodistal angle strongly produced and narrowly rounded. Uropods 1-2 outer ramus little shorter than inner; uropod 3 inner ramus straight, outer ramus with hooked apical spine and 2-3 reverted denticles.
Size:
Up to 10 mm.
Colour:
Greyish with distinct reddish brown markings.
Habitat:
Depth range from to metres, found amongst algae, ascidians, hydroid growths, and on rafts, buoys and other fixed and floating objects.
Distribution:
North Atlantic; not previously distinguished from Jassa falcata.