MOTES-.ON SOME) a5 Pe TiC: SPE CEES: OF 
PALINGENIA (ORDER EPHEMEROPTERA). 
By F. H. Gravey, D.Sc., Asst. Superintendent, Zoological Survey 
of India (now Superintendent, Government Museum, Madras). 
(With Plates XVIII—XX.) 
The Ephemerid genus Palingenia has attracted the attention 
of many naturalists on account of the way in which immense 
swarms of adults hatch and die annually during the evenings of a 
few consecutive days only.! 
The larvae are fossorial. They have six pairs of double gill- 
plumes arched upwards over the back and protected by five 
pairs of lamellae which are covered on the outer side by long hairs. 
According to Swammerdam (1758, p. 109), these lamellae are “ oars 
that serve the creature for swimming.” Male larvae may be 
distinguished from females by their larger eyes and, in the later 
stages, by their longer caudal appendages and developing forceps. 
The genus has been provisionally divided by Eaton (1883, 
p. 23) into three subgenera as follows:—‘‘ Palingenia (typical), 
Burmeister, containing European and Western Asiatic species; 
Anagenesia containing Indo-Malay and a Siberian species; anda 
nameless subgenus containing Brazilian species,’ concerning the 
adults of which scarcely anything appears to be known.” 
Eaton’s system of reference to the venation of the wings ® has 
been adopted throughout the following notes in order to facilitate 
comparison with his monograph. In the figures this system is 
supplemented by that used in Comstock’s book ‘‘ The Wings of 
Insects ’’ (New York, 1918). 
Subgenus Palingenia, Burmeister, s. stv. 
Adult with the fore-tarsus of the male about 2} times as long 
as the femur ; the praebrachial nervure (6) of the forewing forked 
beyond the middle; two conspicuous couples of longitudinal 
nervures (midway between 4 and 5, and 5-6) proceeding to the 
terminal margin of the fore-wing (pl. xx, fig. 21); the forceps with 
a long slender basal joint grooved on the inner side and (? always) 
at least five shorter terminal ones (pl. xx, figs. 22-3). 
| For references see Eaton, 1883, pp. 24-28; also Swammerdam, 1758, p- 104, 
concerning references by more ancient writers. 
2 The larva is figured by Eaton, 1883, pl. xxv, figs. 20-24. 
® Eaton, 1883, p. 4. 
