572 AUTHENTIC HISTOKY 



conflueiis Sai/. MELOPnAorrs? 



falcouis JI(ir. oviuus Linn, 



My scientitic knowledge of the Diptera of Lancaster county is very limited, and 

 therefore the foregoing catalogue of these insects is nothing more than an imperfect 

 compilation from the works of Say, Harris and Fitch — with Harris' classilication — as 

 an approximation to what may be jiresumed to be the dipterous fauna of the county, 

 from its geographical position, and its relation to other portions of the northern and 

 middle States of the Union. S. S. R. 



ORDER APHANIPTERA. 



This is the order Aptera of IMacley, and includes the wingless insects; an example 

 of which is the common "Flea" — Pulex irritans. Not «W insects however, that are 

 destitute of wings, are members of this order; for there are various species, the females 

 of which are wingless, and in some instances both sexes, in other orders. As instances 

 of this kind, it may be remarked, that several species of predaceous Goleopter a v^revfirygs 

 less, although tliey have wing-covers. There are also wingless species both male and 

 female among the Orthopiera; and females among the Hemiptera; and among the Ilynf 

 enoptera, and Lepidoptera, as well as the Diptera. This subject constitutes one of those 

 anomalies in natural history, which can only be solved by the patient and jjersevering 

 progress of the entomological student. The order Aphaniptera might perhaps be properly 

 restricted to a single small family. Pulecid.e, which includes the various species 

 of fleas, that infest men and animals. The Podurid^, which by some entomol- 

 ogists are regarded as degraded species of Neuroptera, may, for the present with 

 some proprietj', beplaced in this order. These insects undergo the usual trans- 

 formations, from the egg to the imago, that all other insects do, but they lack the 

 distinctive divisions of head, thorax and abdomen, that characterizes the other ordei's, 

 being merely a series of segmental rings, from the head to the caudal termina- 

 tion of the abdomen. In their larva state they are long, distorted, wormlike grubs, 

 which however spin themselves into a sort of silken coccoon, and assume the pupa form, 

 in which the legs, antennae, and sucking apparatus are visible. Emerging from this 

 state, they assume the mature form, in which i\\e P^llecid(e have the hind feet developed 

 into leaping appendages, and the external integument tough and shiny, each segment 

 being fringed with a few stiff bristles. In this fonn they attack men and animals, living 

 upon the blood they extract from them by means of their powerful piercers. 



PULECID^E. arvalis Fell. 



elegans Fell. 

 PuLEx Lin. noveboracensis Fell. 



irritans Lin. "Common Flea."' signifer Feh. 



PODURIDJE. 



PODTJRA. 



nivicola Fell. 

 Stmuthurus? , Several other species. 



hor tensis i^c7t. Thysanitra. "Spring-tails." 

 juvenilis Feh. Several species, 



dorsalis Fell. Lepisma. 

 apicalis Fell. Several species, 



maturus Fell. 



The Fodundce, as before stated, are regarded by many naturalists as merely degraded 

 forms of Neuroptera, allying them with the genera Ephemera and Perla, and therefore 

 perhaps they cannot j^roperly be classed with the Order Aptera, scientifically restricted. 



