GENUS VERRUCA. 509 



with the usual apodeme and muscles. The Outer Maxilla 

 are prominent, and deeply lobed on their inner surfaces, 

 the two lobes being clothed with bristles. 



Cirri. — The first pair are attached, as usual, on each side 

 of the mouth, and stand some way apart from the five pos- 

 terior pairs. The second and third pairs differ considerably 

 in structure from the three posterior pairs, which are much 

 elongated. The first pair (excepting in V. nexa) is short, 

 with the two rami slightly unequal in length, and with the 

 segments thickly clothed, as usual, with spines. The second 

 pair is remarkable from the posterior ramus being more 

 than twice as long, and containing thrice as many segments, 

 as the anterior ramus, which is barely as long as the shorter 

 ramus of the first pair : the segments in the anterior ramus 

 of the second pair (only five in number in a full-sized speci- 

 men) are broader and more protuberant in front, and more 

 thickly clothed with spines (the terminal spines being doubly 

 pectinated), than are the segments on the posterior ramus ; 

 on the latter, the uppermost segments have their bristles 

 arranged in front in simple pairs, with the dorsal spines 

 long, the lower segments being more thickly clothed with 

 bristles, owing to the development of lateral rows. The 

 third pair resembles in every respect the second pair, ex- 

 cept in being a little longer, and in the bristles on the poste- 

 rior ramus being less crowded, more resembling the arrange- 

 ment of those on the posterior cirri. In V. nexa, however, 

 there is not so great an inequality in length or dissi- 

 milarity in structure in the two rami of the second cirrus, and 

 only a very slight difference of any kind in the two rami of 

 the third pair. Fourth, fifth, and sixth pairs have numerous 

 elongated segments, bearing four or three pairs of long 

 slender spines in front, with a single minute bristle between 

 each pair, and with two or three slender spines in the dorsal 

 tuft. 



There is a considerable amount of variation in the pro- 

 portional length, and in the number of the segments, of 

 the several cirri in V. Stromia ; in some specimens the two 

 rami of the fourth pair were unequal in length ; in some, 

 nearly all the cirri on the lower or attached side were shorter 

 than those on the upper side. 



