90 THE CANADIAN ENTOMOLOGIST. 



Thorax gray, without marks ; abdomen paler, in the female terminating 

 somewhat squarely. 



Expanse 40 to 42 mil. Habitat Nevada, Colorado (Dr. Bailey and 

 Mr. Graef.) 



Except in the antenna?, and possibly the unlashed eyes, this species 

 seems to agree with Lederer's definition of Polia. It is to be recognized 

 by the even median lines, the jagged angulated subterminal line, the 

 difference in the tint of the hind wings in the sexes, and its effaced and 

 inconspicuous ornamentation. 



ON THE LARVAL CHARACTERISTICS OF CORYDALUS AND 



CHAULIODES AND ON THE DEVELOPMENT OF 



CORYDALUS CORNUTUS. 



BY PROF. CHAS. V. RILEY. 



(Abstract. ) 



The paper relates to the development of one of the most singular and 

 interesting of North American insects — the largest of the Order Neurop- 

 tera. In its perfect state this insect is a great, clumsy, nocturnal fly, 

 popularly called Hellgrammite, and characterized by the jaws of the male 

 being converted into a pair of long, curved, cylindrical and tapering pre- 

 hensile organs, like the finger of a grain-cradle. In the larva state it is 

 aquatic and much esteemed as fish-bait by fishermen, who call it a 

 " crawler," " dobson," etc. Indeed, one of the most popular artificial 

 fish-baits is a patent india-rubber imitation of it. This larva is very 

 peculiar in having in its latter stages three distinct sets of breathing 

 organs, viz. : the ordinary spiracles, a lateral series of long, single bron- 

 chial filaments, and a ventral series of spongy branchiae, composed of 

 numerous branching and tractile filaments. The eggs of this insect are 

 laid, to the number of about three thousand, in curious masses on the 

 leaves and branches of trees, or upon any other object overhanging 

 water, and were first described by Mr. Riley at the Buffalo (1876) meeting 

 of the Association. After comparing the eggs with those in the female 

 abdomen, and the newly hatched with the mature larva, he felt quite 



