1920. | F. H. GrRAvELy: Asiatic Palingenta. 139 
‘“ The larvae of Palingenia were collected about the end of 
November at the edge of small pools of very foul water left by the 
retreat of the annual floods in the bed of the Randa stream near the 
ruined city of Jellalabad, some twelve miles north of Nasratabad, 
the capital of Seistan. This stream is filled with water only in 
flood-time. For some considerable distance south the country 
consists of a flat barren plain the surface of which in winter is formed 
of bare and extremely hard grey clay. It isin fact one of those 
shallow basins, so common in Seistan, which are flooded every 
normal year by the rise of the Helmand. ‘Towards the edge of 
this basin we noticed that the whole ground was pitted with 
little holes as though a rather narrow pen-holder had been re- 
peatedly thrust into it. We were unable to account for this 
phenomenon until we examined the edge of the pools, where each 
hole was occupied by a Palingenia larvae. The mud was here 
fairly soft but was caking rapidly and the larvae, the gills of 
which were pressed tightly against the sides of their abdomens, 
were, though still living, apparently being gradually asphyxiated. 
The foulness of the water was due partly to the presence of large 
numbers of dead fish and partly to the fact that the several tribes 
of the district watered their flocks of sheep and goats at the pools. 
Doubtless the Mayflies of the same genus collected in large 
numbers in Seistan by the officers of Sir Henry MacMahon’s Com- 
mission were captured in spring or summer.” 
The identity of Dr. Annandale’s larvae with these adults from 
Seistan is extremely probable, but has not been definitely proved. 
The larvae appear to be identical with those of P. /ongicauda des- 
cribed by Swammerdam (1758) and Cornelius (1848). The caudal 
appendages are not very well preserved ; they seem to be of 
almost equal length in both sexes, but this is probably due to their 
not being fully developed. ‘These larvae differ from all other Palin- 
genta larvae yet known in having the dorsal (outer) margin of both 
the mandibles and fore-tibiae very strongly toothed. 
I have not been able to distinguish the second spine figured by 
Cornelius on the blade of the maxilla; but this may be a variable 
character (see below, p. 142). The labial palps bear hairs and spines 
like those of P. robusta. 
The front legs closely resemble those of P. robusta. The 
group of spines on the inner side of the lower distal angle of the 
tibia is, however, composed entirely of simple spines somewhat 
longer and slenderer than the very stout simple spines of the outer 
half of the group in that species. The serrate spines on the tarsus, 
on the contrary , are somewhat coarser ; they are also more numerous. 
The middle legs differ from those of P. vobusta chiefly in the pre- 
sence of a large conical tooth on the dorsal surface of the distal 
end of the tibia. The hind legs differ chiefly in having the outer 
distal angle of the tibia less produced. In both middle and hind 
legs the spines on this angle resemble those found in the same 
position on the front legs; they are much thinner than in 
P. robusta, 
