on the Hphemeride. 4.9 
Heptagenia zebrata.. : Corsica. 
is [gemmata] : “Circa aqueductum Fodinarum Idren- 
sium.”’ 
PA guttata . : Valdivia, Chili. 
5 torrida  . e Philippine Isles. 
aS determinata . Java. 
Thus, the number of described recent species of Hphe- 
meride is about 178, exclusive of ten which are either 
hardly determinable, or probably mere conditions of well- 
characterised forms which have been otherwise named. 
There are three fossil species determinable. 
EPHEMERIDARUM GENERUM RECENTIUM SUMMA ANALYTICA. 
Metathoracic wings present 
Metathoracie wings wanting 
1 
3 long subequal caudal sete 
2 
Cloeon, Pl. IL. f. 7. 
Cross-veinlets of wings numerous towards the anterior margin; 
Gen. XII; Tricorythus, Pl. II. f. 3. 
Cross-veinlets of wings disposed in very few transverse rows ; 
Cenis, Pl. II. f. 4. 
Longitudinal neuration of posterior wings considerably complex 
Longitudinal neuration of posterior wings ee Cs 23. pect 
4 
nervures only) 
Lateral margins of the hinder abdominal segments produced 
into a slender subulate process on each side; Lachlania, 
Pl. I. f. 1; Oligoneuria, P11. f. 2. 
Posterior wings very narrow ; Centroptilum, Pl. II. f. 8. 
6 
Il. f. 9, Pl. Il. £. 
Posterior pairs of legs well developed 
a Posterior pairs of legs very short and feeble . 
Cross-veinlets in the marginal area before the nodus of the an- 
terior wing, few and indistinct 
Cross-veinlets in marginal area before the nodus of anterior 
wing, numerous and well defined; Polymitarcys, P1.I. f. 5. 
Terminal margin of anterior wing free from cross-yeinlets ; 
Campsurus, Pl. I. f. 4 
Terminal margin of anterior wing here and there met by cross- 
Lateral margins of the hinder abdominal segments simple 
5 
veinlets; Asthenopus, Pl. I. f. 3 
TRANS. ENT. soc. 1871.—ParT I, (MARCH.) 
2 long caudal sete; the third rejected ; Gen. “XXII. 993 
Posterior wings ee obtuse ; Gen, XXTT. 9° 2s Baetisy PI. 
ne 
