27S Aiviah KntomoJogical Society of America [\'ol. Ill, 



vessels, the surface of the canal for its whole length is unbroken 

 (Fig. 1). From the exterior the division into fore-, mid- and 

 hind-intestine is distinctly marked. The short, much con- 

 stricted fore-intestine extends back to the third thoracic gan- 

 glion. Here, by means of a strong esophageal valve, it connects 

 with the very large mid-intestine, which in turn extends back to 

 the sixth abdominal segment, where the somewhat constricted 

 hind-intestine begins. 



The opening of the mouth is on the ventral surface of the 

 anterior part of the head. The clypeus and recurved labrum 

 form a rostrum over and in front of it. The labrum bears, on 

 either side of its anterior recurved margin, a fan of bristling 

 hairs (Fig. 3 Ir.) The area between these fans is armed with 

 numerous posteriorly directed, strong setae and minute serrate 

 chitinous plates. Posterior to this area is a strong V-shaped 

 plate and laterad of it, along the margin, a pair of mesally 

 directed triangular plates. Behind the V-shaped plate comes 

 a group of small chitinous plates, arranged in a circle, and a 

 series of minute setae. A pair of small plates, bearing numer- 

 ous minute teeth on their mesal margins, lies laterad of this 

 chitinous ring. Farther back is a pair of lateral tufts of setae 

 and a second pair of oval plates. 



The mandibles are strongly chitinized with numerous 

 lateral setae, a single strong spine, with numerous minute teeth 

 on its inner margin, and two long illumes (Fig. 3, md.) On the 

 inner margin are two series of strong teeth, directed at an angle 

 to each other, and a single posterior thumb-like tooth directed 

 cephalad. The hind margin of the mandible is deeply concave 

 to receive the anterior part of the maxilla. 



The maxillae are but slightly chitinized, with four short 

 stout teeth on their inner margin, a small median plume and a 

 fan of long setae extending the full length of the lateral margin. 

 The palpi are short and thick with six small papillae and num- 

 erous short setae. They are circular in outline and fit into the 

 depressions in the hind margins of the mandibles (Fig. 3, mx.) 



The labium is a fieshy lobe bearing numerous fine setae and 

 ])apillac. On the anterior margin arc two small tufts of short 

 setae and behind these a crescent-shaped chitinous plate (Fig. 3, 

 la). The sense papillae found upon the labrum, maxillae, palpi 

 and labium are so placed as to come in contact with the food 

 as it enters the mouth and therefore arc very j^robably organs 



