AMERICAN APTKRA. 



303 



the Amblycera, while the maxilla was regarded as consisting of 

 only the small terminal lobe However, a closer examination of 

 Ancistrona gigas shows a distinct line on each side separating the 

 stipes from the labium (fig. 5), while in the very large Lcemoboth- 

 rium gypsis it is easy to dissect the stipes off from the head and free 

 from the labium, and attached to it, are also removed the palpus (fig. 

 2, jo ^.) and the single apical maxillary lobe {I.). Hence, we will 

 have to admit that the original description of the mouth parts by 

 Nitzsch is most probably the correct interpretation. The apical 

 lobe of the maxilla is always small and inconspicuous, it is often 

 soft and fleshy (fig. 5, I.), but may be more or less chitinized and 

 bear a row of teeth distally (fig. 2, I.). 



In the Ischuocera the maxillae never have any trace of palpi, but 

 otherwise are like those of the Amblycera. 



The labium (figs. 1 and 5, lab.) is large and is usually composed 

 of a menturn and a submentum. The distal edge of the mentum is 

 produced into several small lobes of which the outer ones are re- 

 garded by most authors as the rudimentary labial palpi. They vary 

 much in shape and size in the Amblycera where the maxillary palpi 

 are present, being sometimes inconspicuous as in Ancistrona gigas 

 (fig. 5), or comparatively large articulated lobes as in Lcemoboth- 

 rium gypsis (tig. 1, pi.). In the Ischnocera they are always cylin- 

 drical in shape, and, although short, project prominently from the 

 mentum. The margin of the labium between the palpi is some- 

 times entire (fig. 1, lab.), but is more frequently produced into two 

 or more lobes. A pair of large, thick, biramous processes arises 

 from the submentum of Ancistrona gigas and projects backward 

 (not shown in figure). 



The fur cos maxillares (fig. 1,/. and fig. 7) have been discovered 

 by the writer in three Mallophagan species, viz. : Goniodes cervini- 

 cornis, Ancistrona gigas and Lamobothrium gypsis. Since, how- 

 ever, they are extremely small, the fact that they have not been 

 found in other species does not prove their absence in them. These 

 maxillary forks are two delicate bars of chitin embedded in the 

 floor of the mouth. Their distal ends project free into the mouth 

 cavity beyond the edge of the labium and above the hypopharynx 

 (fig. 1,/.). The tip of each is bifid in Ancistrona gigas (fig. 7) and 

 divided into three small lobes in Ltemobothrium gypsis (fig. 1,/.). 



TRANS. AM. ENT. SOC. XXXI. AUGUST, 1905. 



