i 



I I 



1919] Claassen: Chlaeniiis Impunctifrons 97 



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about a little but soon fell over on its back again. In this 

 condition the larva remained on top of the sand for sixteen 

 days without taking any food. On June 27th the larva pupated. 

 The pupa remained quietly on its back till July 4th, when the 

 adult emerged. The adult was rather weak. The legs, especially 

 the metathoracic legs, were not fully developed. The adult 

 specimen was determined by Dr. J. C. Bradley. 



TABLE OF INSTARS. 



LENGTH OF STAGE 



Egg found May 24 



Egg hatched June 1 Egg stage 7 days plus? 



First molt June 3 First instar 3 days. 



Second molt June 6 Second instar 3 days. 



Pupation June 27 Third instar 21 days. 



Emergence of adult July 4 Pupal period 7 days. 



DESCRIPTION OF STAGES. 



MUD CELL. 



(Plate VI, Fig. 5). 



The little mud ball which encloses the egg is made of fine gray sand. 

 It is placed singly on the upper surface of a Typha leaf six to eight 

 inches from the tip. The mud ball is oblong oval, somewhat depressed. 

 It measures 3.43 mm. in length, 2.28 mm. in width, and 1.75 mm. in 

 thickness. 



EGG. 

 (Plate VI, Fig. 1). 



In the center of the mud cell occurs the egg. It is oblong oval, of a 

 glistening white color, with rather large faint reticulations. It measures 

 2.28 mm. in length and 1 mm. in its greatest diameter. 



FIRST INSTAR LARVA. 

 (Plate VI, Fig. 3). 



Color. General color of larva dark brownish black, except in the 

 less chitinized places which are grayish white. Head yellowish brown 

 with a dark brown area in front between the epicraneal sutures. Antennae 

 and maxillary palpi dark brown, with a narrow yellow-brown ring at 

 the joints. 



Form. The body is elongate, tapering to both ends, but more 

 posteriorly. The ninth abdominal segment bears two processes which 

 equal the combined length of the pro- and meso thorax. The anal 

 tube projects posterio-ventrad from the ninth abdominal segment. 



Head. Head, excluding mouthparts and appendages, wider than 

 long, narrowed behind the eyes. Dorsal surface slightly convex, with 

 two short oblique grooves terminating at the lateral margin. Ventral 

 surface more convex. Edge of labrum roughly toothed, with one larger 

 tooth on each outer angle of the anterior margin. Surface of head smooth 



