NEUROPTERA 67 



certain exotic forms, but more of them are terrestrial; some when full- 

 grown enter the ground and make earthen cells in which they transform, 

 but most of them spin cocoons. The silk of which these cocoons are 

 made, in the case of those in which the silk-organs have been described, 

 is secreted by modified Malpighian vessels and is spun from the anus. 



The known Neuroptera of the world represent twenty families. 

 Thirteen of these families are represented in North America; these can 

 be separated by the following table. 



TABLE OF THE FAMILIES OF NORTH AMERICAN NEUROPTERA 



A. Prothorax as long as or longer than the mesothorax and metathorax combined. 



B. Fore legs greatly enlarged and fitted for grasping, p. 71 Mantispuxe 



BB. Fore legs not enlarged and not fitted for grasping, p. 71 Raphidiid^e 



AA. Prothorax not as long as the mesothorax and metathorax combined. 



B. Hind wings broad at base and with the anal area folded like a fan when not in 



use. p. 68 Sialid^e 



BB. Hind wings narrow at base and not folded like a fan when closed. 



C. Wings with very few veins and covered with whitish powder, p. 73 



Coniopterygid^; 



CC. Wings with numerous veins and not covered with powder. 



D. Antennae gradually enlarged towards the end or filiform with a terminal 

 knob. 

 E. Antennae short; wings with an elongate cell behind the point of fusion 



of veins Sc and R x . p. 70 Myrmeleonid^e 



EE. Antennae long; wings without an elongate cell behind the point* of 



fusion of veins Sc and Ri. p. 73 AscalaphiD/E 



DD. Antennae not enlarged towards the end. 



E. Male with pectinate antennae; female with an exserted ovipositor. 



p. 7 2 •.■••: Dilarid^e 



EE. Antennae not pectinate in either sex; female without exserted ovi- 

 positor. 

 F. Radius of the fore wings with apparently two or more sectors. 



G. Radius of the fore wings with apparently two sectors, one of which is 



vein R.2+3 and the other vein R 4 +5. p. 72 Sympherobiid^e 



GG. Radius of the fore wings with three or more sectors. Veins R 4 

 and R 5 arise separately from vein Ri; one or more definitive acces- 

 sory branches of the radius of the fore wings present, p. 72 



• • HeMEROBIIDjE 



FF. Radius of the fore wings with a single sector. 



G. Radial sector of the fore wings without definitive accessory veins 

 although marginal accessory veins are present, p. 72 .... Sisyrid^e 

 GG. Radial sector of fore wings with definitive accessory veins. 

 H. Transverse veins between the costa and subcosta simple, p. 69 



Chrysopid^e 



HH. Many of the transverse veins between the costa and subcosta 

 forked. 



I. Humeral cross-vein recurved and branched; first radio-medial 

 cross- vein of the hind wings longitudinal and sigmoid, p. 73 



POLYSTCECHOTIDiE 



II. Humeral cross- vein not recurved; first radio-medial cross- vein 

 of the hind wings transverse, p. 73 Berothid^e 



Of the foregoing families but three are of common enough interest to 

 justify any extended discussion in this brief work. These are the Sialidae 

 which embraces the horned Corydalus and the fish-flies, the Myrmelionidae 

 which includes the curious ant-lions, and the Chrysopidae or lacewing-flies. 

 The lesser known families are grouped at the end of the chapter. A more 

 extended discussion of them may be found in "An Introduction to 

 Entomology" by J. H. Comstock. 



