PERLIDES. 177 



Genus 6. NEMOUEA. 



Palpi filiformes. Abdomen setis nullis. 



Nemoura, Latr. 

 Phryganea p., Linn. 

 Perla p., Geoffr. 

 Semblis p., Burm. 

 Nemoura et Leuctra, Steph. 



Sub-genus 1. TCENIOPTERYX. 



Palpi labiales mediocres, remoti. Abdomen setis tribus triar- 

 ticulatis brevissimis terminatum. Tarsorum articuli longi, sub- 

 aequales. AlaB plerumque involutes, cinereo et albido saepe fasciatae. 

 Parastigmatis venae X non fingentes. 



To3niopteryx, Pictet, Hist. Nat. Neur. Perl. 343, pi. 42, f. 4. 



Veins of the parastigma not forming an X : labial palpi middle- 

 sized, far apart: abdomen terminated by very short rudimentary 

 three-jointed tail-bristles : joints of the tarsi long, almost equal : 

 wings generally involved into a half cylinder, often with gray and 

 whitish bands. 



Div. 1. 



Alae fasciis cinereis plus minusve distinctis. 



Subdiv. 1. 

 Alae fasciis tribus valde distinctis, maris rudimentales. 



1. NEMOURA TRIFASCIATA. 



_ fi g . ? Schceff. Icon. pi. 37, f. 2, 3. Abhandl- 



Ins. Mem. 7. 

 Nemoura trifasciata, Pictet^ Ann. Sci. Nat. xxvi. 379, 3, pi. 15, f. 



4 10; M6m. Soc. Phys. Geneve, vii. 178; Hist. Nat. Neur. 



Perl. 351, 2, pi. 44, 45, f. 15. Zett. Ins. Lapp. 1057. 

 Brachyptera trifasciata, Newport. 



a, b. England. 



c. Dartmoor. From Dr. Leach's collection. 



