169 



109. Amphiaseus intermedius (Scott). 



(PI. CX). 



Stenlielia intermedia, Th. Scott, Marine Invertebrata of Loch Fyne, 15th Ann. Rep. of the Fishery 

 Board for Scotland, p. 169, PI. II, figs. 1021. 



Specific Characters. Female. Body much shorter and stouter than in the 

 2 preceding species. Cephalic segment rather broad and evenly rounded in front; 

 rostrum distinctly bifid at the tip. Caudal rami much broader than they are 

 long, apical setse remarkably short and moderately thickened at the base. An- 

 terior antennse of a structure similar to that in the 2 preceding species, though 

 having the last joint somewhat larger, nearly equal in length to the 3 preceding 

 joints combined. Posterior antennae scarcely differing in their structure from 

 those in the above-mentioned species. 1st pair of legs likewise of a very similar 

 structure, outer 2 joints of inner ramus rather short, together scarcely attaining 

 half the length of the 1st. Natatory legs almost exactly as in the 2 preceding 

 species. Last pair of legs with the distal joint somewhat tapered distally and the 

 marginal setse comparatively shorter than in those species; inner expansion of 

 proximal joint triangular, extending slightly beyond the middle of the distal joint. 

 Ovisacs rather large and diverging considerably. 



Male with the 2nd basal joint of 1st pair of legs produced inside to a 

 highly chitinized tenon-like projection similar to that found in the male of A. his- 

 pidus, the tip of the projection, however, being less blunted. Inner ramus of 2nd 

 pair of legs transformed in a manner very similar to that in the male A. his- 

 pidus, the bayonet-shaped terminal projection being, however, somewhat shorter 

 and having on the outer side 2 strong serrulations not found in that species. 



Colour yellowish grey. 



Length of adult female 0.74 mm. 



Remarks. This is unquestionably the species recorded by Th. Scott in 

 the above-named paper as Stenlielia intermedia. Though closely related to the 

 2 preceding species, it may be at once distinguished from either of them by its 

 much shorter and stouter body, as also by the distinctly bifid rostrum and the 

 unusually short caudal setse. 



Occurrence. Some few specimens of this form were taken at Levanger, 

 on the Trondhjem Fjord, and at Kopervik, on the west coast of Norway, in depths 

 ranging from 20 to 30 fathoms. 



Distribution. Scottish coast (Scott). 



