442 CALIFORNIA ACADEMY OF SCIENCES. 



the mentum itself. Where the pouch joins the mentum, 

 however, it is narrower than it is a short distance below; 

 it therefore expands a little ventral to its dorsal border. 

 In a mounted specimen the pouch may be pressed down 

 flat against the rest of the labium, and then its anterior 

 border appears to be a fold of membrane extending over 

 the ventral surface of the ligula from the anterior edge of 

 the mentum. Within this pouch are two large glands (plate 

 lxi, fig. 5) lying side by side, one on each side of the me- 

 dian line. They are narrower anteriorly where they open 

 into the mouth cavity near the anterior edge of the labium. 

 Posteriorly they become enlarged and turn outward. 



The ligula is composed of glossae and paraglossae. 

 The glossas are flattened lobes, one on each side of the 

 middle line, and separated from each other for about two- 

 thirds their length. Each is about as wide as long, and 

 the anterior border slopes slightly outward from within. 

 The outer borders are straight. The paraglossae lie just 

 exterior to the glossa?. Each is conical with the end 

 truncated, and is a little longer than the glossag. 



The maxillce (plate lxi, figs. 1 , mx, and 3) are simple lobes 

 expanded distally but narrow at the base. Each projects 

 inwardly and forward, and lies just back of the mandibles 

 of the same side. The ends are exposed in front of the 

 labium. The length is much greater than the greatest 

 width, and the borders are all convex except the posterior 

 two-thirds of the outer, which is a little concave. The 

 anterior and inner edges form a continuous curve, and 

 along these borders the maxilla is strengthened by a chit- 

 inous thickening. Along the anterior margin and the 

 anterior part of the inner, is a series of chitinous teeth 

 which are not very sharp and have their points mostly di- 

 rected inwardly. Each is a continuation of a plication, 

 or thickening, on the maxilla outside the chitinous mar- 



