NEW MALLOPHAGA. 447 



The maxillce (plate lxii, fig. 4) are simple, fleshy, un- 

 chitinized lobes attached to the lateral parts of the mouth- 

 cavity, back of the mandibles. They show no indica- 

 tion of division into different sclerites. Near their bases 

 they are somewhat thickened; the distal ends are weak 

 and almost membranous, in mounted specimens they gen- 

 erally appear twisted and distorted. On account of the 

 position of the labium the maxilla? are mostly exposed, 

 only the bases being concealed. Each projects forward 

 and inward. 



The mandibles (plate lxii, figs 1 and 5) present a very 

 strange appearance, both on account of their shape and 

 their position. They are large, heavy, and strongly chit- 

 inized, and very remarkably different from those of 

 Ancistrona and Ltemobothrium in the way they are at- 

 tached to the head. In these two genera the mandibles 

 lie in a plane parallel to the head, and move in this 

 plane. In order that this may be so, their articulating 

 surfaces are in the same or nearly the same dorso- 

 ventral line. In Eurymetofius taurus there are two artic- 

 ulating surfaces as before, but the mandibles move in a 

 plane which forms a large angle with the horizontal plane 

 of the head. To accommodate this action the articu- 

 lating surfaces lie one in front of the other. The plane 

 of the mandible is, however, not at right angles to that of 

 the head, and consequently the anterior articulation is a 

 little dorsal to the posterior one. In the next form to be 

 described, Goniodes cervinicornis, the mandibles are al- 

 most or quite at right angles to the head, thus present- 

 ing an advance in this respect beyond Eiirymetofius. In 

 either of these two genera the mandibles may be regarded 

 as being the same, typically, as in the Amblycera; but 

 that each has been revolved on an axis passing from the 

 tip of the inner basal process to the articulating condyle, 



