NEW MALLOPHAGA. 457 



of Eurymetopus taunts. Besides these, however, there 

 are two forked rods projecting into the mouth cavity, as 

 in the case of Anciitrona gigas. These rods are ex- 

 tremely slender and difficult to dissect, but they lie just 

 dorsal to the labium, and pass forward beneath the 

 oesophagus, and ventral to the glands connected with the 

 pharyngeal sclerite. Only the bifid tips project into the 

 mouth. Near the anterior end muscle fibres are inserted 

 which pass forward and downward to their origin on the 

 dorsal side of the labium. These evidently serve to 

 draw the rods forward. Those of Ancistrona gigas, 

 which is enormous amongst Mallophaga, are almost invis- 

 ible to the naked eye, being weakly chitinized, and only 

 .5 mm. long by .05 broad at the widest place. Only one 

 specimen of the species of Ecemobothrium described was 

 had for dissection, and the rods may have been present 

 but overlooked. Also it cannot be stated that they do 

 not occur in Eurymetopus taurus. It is to be noticed 

 that the genera Ancistrona and Goniodes belong to the 

 two different subgroups of the Mallophaga. 



Resume. 



From these detailed accounts of the mouth-parts of four 

 genera of Mallophaga, equally divided between the two 

 principal groups of the order, we may confidently make 

 a summary statement of the condition of the mouth struct- 

 ures of the Mallophaga. 



The mouth-parts are confined to the ventral aspect of 

 the much flattened head, the frontal margin of the head 

 being formed by the greatly developed clypeus. The 

 labrum is the foremost of these ventrally located mouth 

 structures, and is well developed, serving for prehension, 

 and in some cases as a disk or platelike sucker for attach- 



Proc. Cal. Acad. Sci., 2d Ser.. Vol. VI. ( 32 ) November 9. 189(i. 



