new mallophaga. 445 



The Mouth-Parts of Eurymetopus taurus. 



(Plate lxii, figs. 1-8.) 



There are many striking differences between the mouth- 

 parts of this form and those of either Ancistrona or 

 Ltciuobothriuin. The dissimilarity is most noticeable in 

 the labiums. Ancistrona and Lcemobothrtum both belong 

 to the suborder Amblycera, while Eurymetopus and the 

 next form to be described, Go n lodes, belong to the sub- 

 order Ischnocera, and the differences presented by these 

 four genera are typical for the two groups. 



In Eurymetopus taurus the labium (plate lxii, figs, i 

 and 6) is reduced in size, and very much crowded back 

 on the posterior aspect of the head. Instead of covering 

 over the mandibles ventrally, it leaves them entirely ex- 

 posed, its anterior border reaching only about as far for- 

 ward as their posterior articulations. 



Oh the posterior half of the median ventral surface of 

 the head is a large unchitinized space. This is bounded 

 laterally by the temples, posteriorly by a narrow, gular 

 sclerite, presenting an obtusely angulated, convex, an- 

 terior border, and anteriorly in appearance by the man- 

 dibles, although it is really not bounded at all in front. 

 The area is somewhat heart-shaped, having the apex 

 forward, for the boundaries formed by the temples are 

 convergent forward. 



The membranous labium stretches across the posterior 

 half of this space, while the part in front of the labium 

 forms the mouth-opening. The labium is composed of 

 the full number of sclerites, and of these the submentum 

 is the largest. It is much wider than long; is unchitinized 

 and membranous, and is attached all around, except in 

 front, to the edges of the space just described. Its 

 lateral edges are convex and rounded, while the posterior 

 border is angularly emarginated to receive the convex 



