Dr. Johnston on the British Annelides. 369 



tacular papillae (fig. 5. ), but there is no appearance of jaws. 

 There seemed to be 30 feet on each side, but, from the close- 

 ness and minuteness of the posterior pairs, the number was 

 not very exactly to be counted : they are biramous, the 

 branches widely apart. The dorsal branch (fig. 6.) of every 

 alternate foot carries a scale or elytron, and is armed with 

 spines, various bristles, and a sort of tangled hair, which par- 

 tially covers the scale. It is shorter than the ventral branch, 

 obtuse, somewhat sinuatecl, and contains two spines : the dor- 

 sal fascicle of bristles is long, reflected backwards, the bristles 

 unequal in length, rather slender, sharp-pointed, smooth, and 

 curved: the next fascicle consists of similar bristles but shorter; 

 and there is a still lower fascicle of very slender ones. The 

 ventral branch (fig.' 7.) of the foot is strong, rugose, obtusely 

 conoid, covered with minute transparent vesicles, and armed 

 with five stout bristles, and with a spine of a yellowish colour. 

 The bristles are not extruded from the extremity, but from a 

 sort of projection beneath it : the two upper ones are fili- 

 form, obtuse, and of a dark brown colour ; the two next are 

 most protruded, smooth, paler, with a sharp slightly curved 

 point ; and the under one is short and acutely pointed like a 

 dagger. This branch then is armed with no less than four 

 different sorts of bristles, calculated both to cut and lacerate 

 and to pierce any opposing body ; but besides all these there 

 is a soft filament (inferior cirrus, fig. *], a.) that originates from 

 a bulb near the base, and is long enough to reach considerably 

 beyond the extremity of the foot. This is evidently a feeler, 

 with which the worm acquaints itself with the nature of the 

 opposing body, — whether an enemy that it needs to repulse 

 by the extrusion of its formidable weapons, or a feebler ani- 

 mal that it can overcome and make its prey. To assist its 

 tactic powers there are besides many tentacular filaments on 

 each side, which originate from the dorsal branch of every al- 

 ternate foot : these are smooth and subulate, and, except in 

 their lesser size, resemble the palpi. The spines (fig. 8.) are 

 of a light yellow colour, tapering from a broad base to an ob- 

 tuse point, smooth and transparent: the bristles (fig. 9 — 12.) 

 are brown with a bronzed lustre, various in size and strength, 

 but all of them quite smooth. The surface of the belly has a 



