202 
Psyche 
[Aug.-Oct. 
in which the second and third segments of the limb give off lobe- 
like processes (or “endites”) to form the lacinia and galea, while 
the so-called endopodite of the limb becomes modified to form 
the maxillary palpus, as was discussed by Crampton, 1922, and 
1923. When the extensor muscles of the maxilla, which are at- 
tached to the cardotendon ct of Fig. 2. contract, the point cc 
acts as a fulcrum and the maxilla is opened or extended; and when 
the muscles attached along the sclerite pas and to other portions of 
the maxilla contract, the maxilla is flexed or closed. The basal 
sclerite he bears a process cp to which the tendon ct is attached, 
and from the point cc (where the sclerite he of Fig. 2 articulates with 
the head in the region of the area bearing the label pge in Fig. 11) 
there extends a groove fitting over a ridge on the under side of 
the head in the neighborhood of the region bearing the label pge 
in Fig. 11. The maxilla, however, has been removed from the 
left hand side of Fig. 11, and the right hand maxilla dips be- 
neath the region sm of the labium, so that the articulating point 
of the base of the maxilla with the head region is not seen in Fig. 
11 . 
: The cardo or basal region of the maxilla is divided into a basi- 
cardo he and a disticardo dc, as is shown in Fig. 2. The stipes is 
divided into a true stipes st and a narrow median marginal region 
pas, and the muscles attached to this sclerite may have been res- 
sponsible for its demarcation. Internally, there is a parastipital 
ridge extending along the parastipital suture demarking the 
sclerite pas and there is likewise an internal cardine ridge de- 
marking the sclerite he from the sclerite dc in the cardo. A 
basimaxillary membrane hm connects the maxilla with the region 
in the basal region of the underlip. 
The stipes st bears a lacinia la provided with a fringe of bristles 
If for sweeping the food into the mouth, or for preventing it from 
falling out of the mouth during the movements of lacinia. The 
laciniadentes Id (Fig. 2) or tooth-like processes at the apex of 
the lacinia la are probably used in aiding to comminute the food — 
or to hold the food when it is comminuted (“chewed”) by the 
mandibles. A peculiar appendage ma is called the midappendix 
lacinula, or hamadens, and is present even in such primitive 
.arthropods as the Crustacea. The palpifer pf is bent around on 
