TAKEN AT ALNMOUTH, NOKTHUMBEBIAND. 435 



Outline as seen from above somewhat lozenge-shaped, great- 

 est width behind the middle and equal to about half the length : 

 seen from the side the ventral margin is almost straight, the dorsal 

 forming a very bold and almost semicircular arch (fig. 1) colour 

 deep red, the edges of the abdominal segments uncoloured : 

 rostrum (fig. 3) short, broad and blunt, slightly emarginate 

 at each side where there is attached a short hair ; abdominal 

 segments slightly spinous at the lateral angles, caudal seg- 

 ments short and stout, about as broad as long, principal tail 

 setae as long as the body of the animal, lateral setae only about 

 one-sixth as long ; those of the male are of the usual width 

 (fig. 1), those of the female (plate XII., fig. 8) dilated and 

 spatulate proximally. Anterior antenuis of the female (figs. 3, 

 4) five- jointed, the first joint very large and stout and produced 

 into a hood-like process which overhangs the second joint, 

 second joint much smaller than the first, but stouter than the 

 remaining three; in the male the antennae are swollen and genicu- 

 lated, with a clawed apex (fig. 5). Posterior antennae scarcely 

 shorter than the anterior and quite as stout, destitute of any 

 secondary branch but bearing at the apex four stout claw-like 

 setae, the penultimate joint also bearing similar setae. Mandible 

 (fig. 8) extremely small, almost obsolete, and provided with a 

 small bisetose, two-jointed palp : the remaining mouth-organs 

 consist of a series of minute filamentous appendages (fig. 7) ar- 

 ranged on each side of what appears to be a suctorial, protrusile 

 mouth. Outer branch of the first pair of feet three- jointed, 

 each joint bearing a stout, curved marginal spine, the apical 

 joint having in addition three long terminal setae (figs. 9, 10) ; 

 outer branch two-jointed, bearing two apical setae, which in the 

 female are simply curved, but in the male are shorter and stouter, 

 divergent and bulbously dilated at the bases : the second, third, 

 and fourth pairs of feet have both branches three-jointed (figs. 

 11, 12) and bear very long and delicately plumose setae, fifth 

 pair (Plate XII., fig. 16) very minute, each foot consisting of a 

 subquadrate lamina tapered and furcate at the distal end. The 

 feathering of the setae as represented in fig. 11. is much too 

 coarse and is in fact scarcely perceptible except with higher 



