PEBLIDES. 141 



Genus 4. PEELA. 

 Palpi setacei. Alae venosae. 



Perla, Geoffroy ; Fair. ; Latr. ; Newman ; Curt. ; Steph. ; Pictet ; 



Burm. 

 Diura, Billberg. 



Maxillary palpi of moderate length ; first joint short; second, 

 third, and fourth larger, not dilated ; fifth straight : mandibles and 

 maxillae of moderate size, or small : wings veined, with only a few 

 cross-veins ; eighth abdominal segment without an inferior prolon- 

 gation in the female : tail-bristles long. 



Group I. DICTYOPTERYX. 



Caput pavvum. Alae rotundatae. Venae longitudinales saepe 

 irregulares. Regionis submarginalis pars terminalis venis transver- 

 sis divisa. Alarum posticarum regio analis magna, plicata. 



Dictyopteryx, Pictet, Hist. Nat. Neur. Perl. 143. 



Anal region of the hind-wings large, folded ; terminal part of 

 the submarginal region divided by cross-veins ; longitudinal veins 

 of this same part often irregular: head small : maxillae multiden- 

 tate : wings large, rounded. Colour of the body almost always 

 black, with a yellow stripe on the head and on part of the thorax. 



1. PERLA INTBICATA. 



Flava ; prothorax longitudine multo latins, vitta Jlava ; alee ob- 

 scure fusees, dense reticulates, regione submarginali irregulari- 

 ter reticulata. 



Perla intricata, Pictet, Hist. Nat. Neur. Perl. 152, 1, pi. 7, f. 18. 

 Ramb. Hist. Nat. Ins. Neur. 452, 5. 



Chamounix. 



2. PERLA MICROCEPHALA. 



Flava; prothorax longitudine multo latius, vitta Jlava; alae pallide 

 fuscce, mediocriter reticulates. 



Perla bicaudata ? Linn. Syst. Nat. ed. 12, 908, 1. Faun. Suec. 

 1489. Gmel ed. Syst. Nat. i. 2631, 1. Barbut, Gen. 216. 

 Berk. Syn. i. 150. Stew. Elem. Nat. Hist. ii. 213. Turt. Syst. 



