of the Fishery Board for Scotland. 115 



specimen represented by the drawing (fig. 11) measures only "56 mm. 

 (about -jj of an inch). In this form the rostrum is small and the furcal 

 joints short. 



The antennules (fig. 12) are elongated and slender and composed of 

 eight joints, the smallest joints counting from the proximal end are the 

 fifth and seventh, while the second is the largest. The proportional 

 lengths of the various joints are shown approximately by the annexed 

 formula : — 



Lengths of the joints, - 15 * 18 • 12 • 11 ■ 7 • 8 • 5 * 8 



Numbers of the joints, - l*2*3'4'5-6'7*8 



The antennas appear to be two-jointed and moderately stout, but the 

 secondary branch is small and composed of a single joint (fig. 13). 



The mandibles are very small and of a cylindrical form, the distal end 

 is obliquely truncated and armed with minute spines ; the palp is also 

 very small, and has the basal part slightly dilated and provided with a 

 minute one-jointed branch (fig. 14). 



The second maxillipeds are moderately stout and two-jointed, and 

 armed with an elongated and slender terminal claw (fig. 15). 



The first pair of thoracic feet have the inner branches elongated and 

 moderately stout ; the first joint is about three times as long as the entire 

 length of the second and third joints, but these two joints are small and 

 sub-equal. The outer branches are moderately slender, and they are 

 shorter than the first joint of the inner ones (fig. 16). 



The next three pairs are all elongated and moderately stout. In the 

 second pair (fig. 17) the inner branches, which are somewhat shorter than 

 the outer, taper towards the distal end, as shown in the drawing, the first 

 joint being more dilated than the second, and the second than the last ; 

 each of the three joints is furnished with a slender seta on its inner 

 margin. The outer branches are slender, and the exterior marginal 

 spines are elongated ; the second joint is also provided with one, and the 

 third with two slender setae on the inner edge. 



In the fourth pair the inner branches are also, as in the second pair, 

 shorter than the second branches, but they are scarcely so stout as those 

 of that pair ; moreover, the first and second joints are each furnished with 

 a seta on the inner margin, while the third bears two setae. The outer 

 branches do not differ much from the same branches in the second pair 

 (fig. 18). 



In the fifth pair the inner produced portion of the basal joint bears four 

 slender setae on its broadly rounded apex, the second one from the inside 

 being much longer than the others. The secondary joints are sub- 

 cylindrical in general form, but with the ends rounded ; they are each 

 about twice as long as broad and carry five setae round the outer margin 

 and apex, but the two innermost are considerably longer than the others 

 (fig. 19). 



Habitat. — Off Musselburgh, Firth of Forth ; apparently rare. 



Remarks. — This is one of those troublesome forms which, while 

 differing in one or other of its structural details from any of the described 

 species I am acquainted with, yet exhibits no single character prominently 

 distinctive, such as we have in Ameira longicaudata, T. Scott. The 

 following three characters, however, taken in combination will, I think, 

 enable this species to be distinguished — (1) the structure of the somewhat 

 slender antennules, (2) the comparatively long first joint of the inner 

 branches of the first thoracic legs, along with the short second and third 

 joints, and (3) the form and armature of the fifth pair in the female. The 

 male has not been observed. 



