Hardenberg—Studies in the Trophi of the Scarabaeidae. 573 
with short, curved hairs. No sense-cups of any kind are ap¬ 
parent. Caudad from these hairs just mentioned is the usual 
Y-shaped hairy area connecting the labial lobes with the hypo- 
pharyngeal fulcrum, which is here fairly well developed. 
Serica sericea Ill. (PI. XXXII, Pigs. 59-63). 
Epipharynx (Pigs. 59-60). In this species the epipharynx has 
undergone a still greater reduction. At first sight the membra¬ 
nous part of the under side of the labrum appears structureless, 
Upon closer examination, however, we find remnants of the epi¬ 
pharyngeal structure which are here represented by a few 
sense-pits in the median area, bounded laterally by a row of 
hairs. 
Mandibles (Pig. 61). In this insect, as in Dichelonycha, 
the mandibles have become more compact and strongly chiti¬ 
nized, not by an increase of the galea but by a greater develop¬ 
ment of the molar. The width of the galea is reduced, and 
the lacinia, increased correspondingly, ends in a slightly chiti¬ 
nized tooth. 
Maxillae (Fig. 62). All the hairs which usually are pres¬ 
ent on the surface of the galea and the lacinia have disap¬ 
peared, and the entire organ has become stronger and shorter. 
The galea ends in five strong chitinized teeth; the lacinia as 
such is no longer distinct. 
Labial structures. Figure 6 (Plate XXXIY) gives a dia¬ 
grammatic representation of the conditions here. The sub-men¬ 
tum is large; beyond it, when seen from beneath, the mentum 
projects as a narrow transverse sclerite. A lateral view shows 
the mentum moved in over the sub-mentum and bearing the 
three-segmented palpi on its ventral surface. Lateral notches 
on the sub-mentum allow the passage of these palpi, which 
have the appearance of arising from the sub-mentum. 
The anterior edge of the mentum is strongly chitinized and 
is continued posteriorly into a membrane which forms the floor 
of the mouth. No trace is left of hypopharynx and labial lobes; 
lateral rows of hairs, converging caudad and enclosing a Y- 
shaped area, may here represent a remnant of the original con 
