102 



Day: Ephemeroptera 



Fig, 3:26, o, Callibaetis sp., nymph; b, Callibaetis sp., labium of nymph; c, Centroptilum 

 conturbatum, mole genitalia; d, Centroptilum asperatum, male genitalia; e, Centroptilum sp., 

 labium of nymph; f, Centroptilum venosum, male genitalia; g, Baetis devinctus, male genitalia; 

 h, Baetis sp., labium of nymph; /, Baetis thermophilos, hind wing; /', Baetis devinctus, hind wing; 

 k, Centroptilum asperatum, hind wing; /, Centroptilum conturbatum, hind wing; m, Centroptilum 

 convexum, hind wing; n, Centroptilum venosum, hind wing (a,c,d,f,g,i-m, Needham, Traver and 

 Hsu, 1935; b,e,h, Spieth, 1933). 



— Hind wing with 2 or 3 longitudinal veins, of which the 

 first and second are about equal in length; the third, if 

 present, is much shorter, ending near the middle of the 

 hind margin 4 



3. Fore wing 4 mm. in length; fourth segment of forceps 

 1/2 as long as third segment (fig. 3:27d,i); central 

 California coastal sulfurosus Day 1954 



— Fore wing 5 mm. in length; fourth segment of forceps 

 nearly as long as third segment (fig. 3:26i); Eel River 



thermophilos McDunnough 1926 



4. Hind wing with but 2 longitudinal veins, the third 

 wholly wanting 5 



— Third vein present in hind wing, although it may be 

 weakly developed 6 



5. Costal projection of hind wing present (fig. 3:25a); 

 mountains bicaudatus Dodds 1923 



— Costal projection of hind wing absent; Klamath River 



insignificans McDunnough 1926 



6. Second longitudinal vein of hind wing forked 7 



— Second longitudinal vein of hind wing not forked ... 8 



7. Second longitudinal vein of hind wing forked about 3/5 

 the distance from base to distal margin; genitalia of 

 moffati type (fig. 3:27/,A); central California coastal 



diablus Day 1954 



— Second longitudinal vein of hind wing forked about 1/3 

 the distance from base to distal margin; genitalia of 

 inter calaris type (fig. 3:26^,;'); Santa Cruz and Napa 

 counties devinctus Traver 1935 



8. Two strong, well-developed intercalaries between veins 

 2 and 3 of hind wing; veins 1 and 2 convergent (fig. 

 3:256); Santa Clara County .... tricaudatus Dodds 1923 



— Not more than one well-developed intercalary, some- 

 times none, between veins 2 and 3 of hind wing; other 

 faint intercalaries may be present 9 



9. Fore wing about 5 mm. in length 10 



Fore wing 6-8 mm. in length; genitalia of moffati type 



11 



10. Fore wing 5J2 mm. long; genitalia of intercalaris type 

 (fig. 3:27c,Z); central California coastal 



alius Day 1954 



— Fore wing 5 mm. in length; genitalia of moffati type; 

 San Gabriel Mts. and Sonoma County 



adonis Traver 1935 



11. Fore wing 8 mm. in length; no intercalaries in hind 

 wing; Inyo County palisadi Mayo 1952 



— Fore wing 6-6!a mm - > n length 12 



12. Vein 3 of hind wing faint; no intercalary between veins 

 1 and 2 of hind wing, but 1 short intercalary between 



