20 



iiorthern specimens. It is doubtful if any more valid distinction tlian 

 this very common climatic variation exists between the two species of 

 Amphizoa now in onr catalogue. The form josfj;// ? has long ago been 

 recognized as having no specific value. 



Thelarva of Amphizoa (Fig. 5) is a short-legged, compactly built insect 

 about three-quarters of an inch in length, of an umber-browu color vary- 

 ing to nearly black. The upper surface is convex and strongly chitinized, 

 showing cloudy mottlings. which arrange themselves in longitudinal 

 lines, and in dark specimens disappear, leaving several rows of trans- 

 lucent dots and dashes more or less sharply defined. The under sur- 

 face is quite flat and naked. The dorsal shields entirely cover the up- 

 per surface of each segment and extend outward on the sides, forming 

 explanate lobes. These lobes, evenly rounded on the throax, gTow 

 more and more acute posteriorly, and their outer margins give a 

 remarkably regular fusiform outline to the body, which terminates 

 acutely behind. The head is large and prominent, with a group of six 



I ■ ^ 



J 



Fig. 5. — Amphizoa lecontei: larva, enlarged: a. dorsal vievr: c. ventral view: b. head, slio-«"ing month- 

 parts, much enlarged (original). 



ocelli on each side near the ti^ont angles. The antenucie are short, 

 three-jointed, placed just behind the jaws on the side margins. The 

 jaws are deeply channeled within and armed with minute denticula- 

 tions on the lower cutting edge. The buccal cavitv is large, adapted 

 to the mastication of food, and provided with molar plates formed by 

 thickenings of the inner surface of the chi:>eus above and the mentum 

 below. The maxillae are stout, basal pieces surmounted by fom^ -jointed 

 palpi and the two-jointed inner lobes. The under lip is broadly trans- 

 verse and prominent, without ligula, and with short, two-jointed palpi. 

 The legs are widely separated, with six articulations, including the 

 double claws. The abdomen consists of eight segments, and terminates 

 in a pair of short movable spines which enter the eighth segment from 



