352 University of California Puhlimtions. [Entomology 



Stemmatosteres,'' n. gen. 



FEMALE 



Head very thin anteroposteriorly, a little wider than thorax, 

 the greater portion of frontovertex and face lying in one plane, 

 which is very slightly convex ; seen from in front, the outline is 

 rounded, the occipital margin appearing truncate, the length 

 and width about equal; in lateral view (fig. 3, B) the outline is 

 narrowly and irregularly oval, the greatest thickness just below 

 the eyes ; in dorsal view ( with head held vertically ) only the 

 vertex visible, sloping gently backward to the occipital margin, 

 which is abruptly rounded, not sharp, its outline now appearing 

 concave ; occiput with a rather shallow, semicircular excavation 

 on the dorsal half into which the prothorax fits, the neck being 



I 



Fig. 2. Acerophagus paUidiis: A, antenna of female; B, right mandible 

 of male, exterio-dorsal view; C, same, anterior view. 



inserted near the dorsal margin of the excavation, so that the 

 head may be held either vertically or horizontally, the former 

 position apparently being the normal or resting position in life ; 

 frontovertex considerably wider than long, the ocelli absent, the 

 eyes small, oval, coarsely faceted ; face abruptly rounded off to 

 the oral margin from just above the antennal sockets, the scrobes 

 entirely absent ; cheeks a little longer than length of the eyes ; 

 antennae (fig. 3, C) inserted rather far apart and close to the 



3 From ffTefxixaTo<TTepr}s, deprived of stemmata, in reference to the lack 

 of ocelli. 



