PERLIDES. 17 



Genus 6. NEMOURA. 



Palpi filiformcs. Abdomen setis nuUis. 



Nemoura, Latr. 

 Phryganea p., Linn. 

 Perla p., Geojfr. 

 Semblis p., JJurm. 

 Nemoura et Leuctra, Stcph. 



Sub-genus 1. TCENIOPTERYX. 



Palpi labiales mediocres, remoti. Abdomen setis tribus tiiar- 

 ticulatis brevissimis terminatum. Tarsorum articuli longi, sub- 

 aequales. Alae j)lerumque iiivolutae, cinereo et albido sa}j)e I'asciatae. 

 Parastigraatis venae X non fingentes. 



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



V^eins of the parastigma not Ibnning an X : labial palpi middle- 

 sized, far apart: abdomen terminated b^ 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 

 whitigh bands. 



Div. 1. 



AlcD fasciis cinereis plus minusve distinctis. 



Subdiv. 1. 

 Ala) fasciis tribus valde distinctis, maris rudimentales. 



1. Nemoura tiufasciata. 



tig., Schcrff. Icon. pi. 37, f. 2, 3. Ahliandl- 



Ins. Mem. 7. 

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



4 — 10; J/^m. Soc. P/u/s. Geneve, vii. 178; Hist. Nat. Neur. 



Perl. 3.31, 2, pi. 44, 45, f. 1—5. Zett. Ins. Lapp. 1057. 

 Brachyptera trifasciata, Newport. 



a, b. England. 



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



