308 Mr. A. Hancock on a Burrowing Barnacle 



this body is composed of the upper lip, which differs considerably 

 from that of the other Cirripedes. In this it is delicate and 

 horny, being enormously developed and surmounted by a sort of 

 rostrum (figs. 6 & 7 g&h), which projects upwards and forwards 

 and terminates in a slightly produced obtuse point ; the dorsal 

 margin (fig. 7 c) is carinated and minutely denticulated. There 

 are three pairs of mandibles as in the other Cirripedes : the outer 

 pair, /, are each apparently composed of three articulations, the 

 third or terminal one being much compressed, forming an irre- 

 gular oval plate, with the upper end terminating in a tooth-like 

 process curved inwards; the two other articulations are much 

 narrower, but on account of their minuteness and delicacy their 

 form could not be determined with accuracy. Only two articula- 

 tions were observed in the second pair of mandibles, g ; the inner 

 or first articulation is long, thin and straight, with the extremi- 

 ties enlarged, and of an irregular form ; the outer or second joint 

 is very similar to that of the outer pair ; it is however provided 

 with two incurved teeth or spine-like processes at the upper ex- 

 tremity. The innermost or third pair of mandibles, h, are rather 

 wide, squarish plates with three or four stoutish hairs on their 

 upper margin. 



At each side of the mouth there is a stout arm or palp (fig. 6 h 

 & fig. 7 d d) which stands erect and reaches a little above the 

 ridge of the rostrum ; the anterior margin of these arms is a 

 little convex, the posterior a little concave; and they are fur- 

 nished with stout, rather soft pincers about half the length of 

 the arm, covered with numerous long hairs : at the root of the 

 pincers there is an articulation, so that they can be either bent 

 forward or carried erect ; there is also apparently an imperfect 

 joint at the point where the arm joins the side of the mouth, but 

 this could not be determined with certainty, as the horny mem- 

 brane of the limb is so delicate that it is impossible to say whe- 

 ther the occasional flexure at this part is owing to its flexibility 

 or to an articulation. It is difficult to say whether these arms 

 represent what Dr. Martin-Saint- Ange names the jaw-feet in 

 the pedunculate Cirripedes, or the two minute processes that 

 are closely attached to the sides of the mouth in these animals, 

 and which are considered palps by some writers. They seem to 

 occupy the place of the latter, though from their form they have 

 much the appearance of rudimentary anterior feet of the higher 

 Crustacea, 



On each side of the rostrum, extending backwards and a little 

 way below the carinated ridge, there is a series of rather close- 

 set, transverse plates or hairs (figs. 6 & 7 * i) which taper towards 

 their points, and are stout at their origin, where they are slightly 



