87 

 Day: Ephemeroptera 



Fig. 3:8. Male genitalia, a, Rhithrogena petulons; b, R. morrisoni; c, R. brunnea; d, /ronodes 

 lepidus; e, I. californicus; f, I. nitidus (Needham, Trover, and Hsu, 1935). 



Divisions of penes only slightly divergent apically 



4 



Divisions of penes strongly divergent apically 5 



Each division of penes broad at apex; lateroapical 



spines minute (fig. 3:76); Sierra Nevada 



doddsi McDunnough 1926 



Each division of penes narrowed at apex; lateral-apical 

 spines better developed (fig. 3:8a); San Bernardino 



County petulans Seeman 1927 



Each division of penes narrowed at apex; 5-6 small 



apical ventral spines (fig. 3:86); widespread 



morrisoni (Banks) 1924 



Each division of penes broader at apex; mid-ventral 

 spine strong, apical spines less well developed (fig. 

 3:8c); Sierra Nevada brunnea (Ilagen) 1875 



Known Nymphs 



U. Body 7 mm. or less in length (fig. 3:27p) 



decora Day 1954 



Body 9 mm. or longer 2 



Body green brown; gills sometimes rose tinted, legs 

 pale with darker femora marked with a pale V 



doddsi McDunnough 1926 



Body red brown; tergites 8-10 with pale submedian 

 spots; gills sometimes rose tinted; legs pale, outer 

 surface of femora brown with large median dark brown 

 spot and with black apices morrisoni (Banks) 1924 



Key to California Species 

 Male Adults 



1. Each division of penes with ventral spines 2 



— Penes without ventral spines 3 



2. Ventral spines long, distinct; lateral in position and 

 near base of penes; Madera County. . . . par (Eaton) 1885 



— Ventral spines small; subapical in position (fig. 3:5a); 

 central California coastal .. uniformis McDunnough 1934 



3. Wings usually suffused with amber, strongly SO at base; 

 margin of Styligei plate straight; no tracheations on 

 abdominal tergites; widespread (fig. 3:9a) 



mimus (Eaton) 1885 



— Wings evenly and faintly amber tinted; styliger plate 

 slightly produced; prominent dark tracheations on 

 abdominal tergites; Sierra Nevada .... tioga Mayo 1952 



Nymphs 



Femora ochreous, with 2 broad brown bands 



uniformis McDunnough 1934 



Femora ochreous, with pale L-shaped, wide longitudinal 

 mark in center of basal half and another wide, pale 

 area along dorsal margin in basal half 



mimus (Eaton) 1885 



Genus Iron Eaton 



Genus Cinygmula McDunnough 



The nymphs are often found in water only one to two 

 nches deep at the foot of riffles, in crevices, and on 

 jower surfaces of small stones in the small streams 

 pf the Redwood Belt, Coast Range, and Sierra Nevada, only by individual picking. 



Widely distributed at all elevations in rocky streams 

 of good current and moderate to cold temperatures, 

 this typically flattened fast-water nymph is found in 

 the strongest currents of rapids clinging to the under- 

 sides of medium to large boulders. They are removed 



Fig. 3:9. Male genitalia, a, Cinygmula mimus; b, Iron longimanus; c, /. albertae, d, /. sancto- 

 gabriel; e, /. du/c/'ano (Needham, Traver, and Hsu, 1935.) 



