1917] HololeptincB of the United States 373 



which has a sensory bristle at the tip. The swollen segment 

 probably represents subgalea and palpifer fused; the finger-like 

 segment is probably galea. At the apex of this swollen segment 

 is a three-jointed palpus. The second and distal segments 

 of the palpus have numerous sensory pits on the surface. 



The mentum is coriaceous, colored only on the margins; 

 it is closely united to the submentum, which is slightly chitinized 

 and light brown in color. The palpifers are fused and form a 

 hollow tube, bearing two jointed palpi at the distal end. No 

 ligula or paraglossae are present. Above the labium lies the 

 hypopharynx. This has two blades, visible in Fig. 7, which 

 bear numerous bristles on the margin. Limiting the hypo- 

 pharynx on each side is the hypostoma, which extends as a 

 heavily chitinized rod upwards from the base of the mouth 

 cavity, a flattened bridge, the epipharyngeal bracon (Fig. 7), 

 extends between the two rods below the epipharynx (Fig. 3). 



The thoracic segments are sharply differentiated from 

 the abdominal. Pronotum consists of a heavily chitinized 

 scutum, a less heavily chitinized parascutum. The meso- and 

 metathorax show the scutum above. The first abdominal 

 segment has a prescutum, a scutum and postscutum, the 

 remaining abdominal segments have the scutum divided into 

 two parts by a line of ambulacral hooks (reptori^ Schiodte). 

 On all the segments except the prothorax the pleurae are readily 

 distinguishable. On the dorsal side they are limited by muscle 

 marks and on the ventral side there is a distinct sterno-pleural 

 groove. The pleurae are divided into epi- and hypopleurae by 

 the pleural suture. The epipleura of all the segments except 

 the pro- and metathorax bears a biforian spiracle, and a bristle, 

 the hypopleura bears also a single bristle. Prosternum consists 

 of a triangular sternum and two plates on each side of it. The 

 inner one is the parasternum, the outer is pleural in origin. 

 The abdominal sternites show a presternum, a sternum which 

 is cut off from the presternum by a muscle groove and a ster- 

 nellum which is separated from the other two plates by a row 

 of ambulacral hooks. The ninth abdominal segment bears an 

 anal pseudopod, which I believe to be a tenth segment. 



