NEW MALLOPIIAGA. 459 



tally, and bears few to many small teeth. Sometimes the 

 distal part of the maxilla is two-parted and these two parts 

 may represent the galea and lacinia of the typical maxilla 

 of the orthopterous type. The maxillary palpi are com- 

 pletely lost, there being no indication of them on any of 

 the maxilla 1 examined. 



The labium (see, in addition to figures previously re- 

 ferred to, plate lxiii, iigs. i, 2, 3, 5, and 6) shows some 

 considerable variation in the two suborders. In the Am- 

 blycera it is a larger and more complete structure than 

 in the Ischnocera. A distinct submentum, mentum, and 

 ligula are always present, the ligula consisting of the two 

 terminal lobes, glossa, and paraglossa of each constituent 

 half of the labium, united at their bases. With the Am- 

 blycera conspicuous 4-segmented palpi rising from a basal 

 segment-like palpifer are always present; while with the 

 Ischnocera palpi are wanting. The ventral or other sur- 

 face of the labium is in some forms (see Ancistrona gigas) 

 provided with strong backward-projecting, pointed, some- 

 times bipartite processes, as with Ancistrona gigas, Men- 

 opon tridens, Menopon robust it m, and others. These pro- 

 cesses must subserve some holding on or clasping func- 

 tion. 



A hypopharynx of elaborate structure was observed in 

 Ancistrona gigas, but not in the other species dissected. 

 Grosse refers to a delicate membranous fold of the ven- 

 tral wall of the mouth, which in some forms projects be- 

 yond the ligula as the hypopharynx. 



The " forks " observed in Ancistrona and in Goniodes — 

 genera representing both suborders of Mallophaga — be- 

 cause of their similarity to the familiar "forks" of the 

 Psocidae are of exceptional interest, and have not here- 

 tofore been referred to in the literature of the Mallopha- 

 gous mouth-parts. Most plainly discernible in Ancistrona, 



