202 INSECTA. 



They comprise the genus 



Perla, Geoff. 



Their body is elongated, narrow, and flattened ; the head is tolerably 

 large, the antenna? are setaceous, and the maxillary palpi very salient. 

 The first segment of their trunk is nearly square, and the wings are 

 crossed and laid horizontally on the body; the abdomen terminates as 

 usual by two articulated setae. 



Their larvae are aquatic, and inhabit sheaths or cases, which they 

 construct in the manner of those formed by the Insects of the ensu- 

 ing family, and in wliich they pass into the state of nymphs. They 

 undergo their ultimate metamorphosis in the commencement of 

 spring. 



Neumora, Lat. 



The Nemourge differ from the Perlae proper in their very apparent 

 labrum, corneous mandibles, the almost equal length of the joints of 

 their tarsi, and in the setag of the extremity of the abdomen, which 

 are almost wanting *. 



P. bicaudata; Phryganea hicaudata, h.; Geoff., Insect., II, 

 xiii, 2. Eight lines in length; of an obscure brown, with a 

 yellow line along the middle of the head and thorax ; nervures of 

 the wings brown ; setae of the tail almost as long as the antennae. 

 Common in Europe in the spring, along the banks of rivers f. 



FAMILY III. 

 PLICIPENNESf. 



In this family the mandibles are wanting, and the inferior wings 

 are usually wider than the others, and plaited longitudinally. It is 

 formed of the genus 



Phuyganea, Lin. Fab. 



These Neuroptera, at a first glance, have the appearance of little 

 Phalsenae, and hence the name of Mouches papillonacees or papilio- 

 naceous flies, bestowed upon them by Reaumur. De Geer even ob- 

 serves that the internal organization of their larvae bears the closest 

 resemblance to that of caterpillars. Their head is small, and presents 

 two cetaceous antennae, usually very long and salient ; rounded and 

 salient eyes; two ocelli on the forehead ; a curved or conical labrum; 

 four palpi, those of the maxillae commonly very long, filiform, or 



* See Lat., Gen. Crust, et Insect., Ill, p. 210; Oliv., Encyc. Method., article 

 Nemoure ; Phryganea nebulosu, L., &c. 



t Geoff, and Lfvt., Ibid. 



X In the systems of Messr». Kirby and Leach, this family forms the order of the 

 Trichoptera, which would connect itself with that of the Lepidoptera, through the 

 Tineae. But as we naturally pass from the Plicipennes to the Perlae, by following 

 the series of mutual relations, we should he forced to terminate the Neuroptera with 

 the Libellulae and Ephemarie, whose organization and habits differ greatly from thos 

 of tho Hyuienoptera, which according to this method follow the Neuioptera. Th 

 Libellulae and other Neuroptera, which in our system come directly after, appeal" t 

 us to be those which approximate most nearly to the Orthoptera. 



