1940] 
Early Stages of Lepiselaga crassipes 
11 
like structure which seems to be capable of considerable 
extrusion and retraction. Hart (1895) mentions this struc- 
ture as being present in all the Tabanid larvae he examined, 
but noted that it was retractile, so that in many specimens 
it was not visible. He gives a figure of it in lateral view 
for Tabanus nigrescers. Stone (1980) also mentions this 
structure and uses it in his key, it being found in some spe- 
cies of Chrysops and Tabanus but not in others. Such a 
structure would seem quite well adapted to piercing the 
air spaces in the roots and leaves of such aquatic plants as 
Pistia and Piaropus , while allowing the larva to secure air 
from the water surface when such plants are not available. 
In any case, the larvse live quite well under artificial con- 
ditions, apparently not needing aquatic vegetation from 
which to secure air. 
The pupa is 10-14 mm. long, the abdomen relatively short, 
for the head and thoracic region are only slightly less than 
half the total length of the pupa. The head-capsule is 
smooth and rounded, lacking the bosses and rugosities often 
found in other species of the family. The thoracic spiracles 
are produced into relatively long conical trumpets, which 
are directed sidewise with their openings on the ventral side 
of the apex. These elongated thoracic trumpets have been 
found in only one other Tabanid, so far as I am aware. 
King (1926) records similar structures for Tabanus fascia- 
tus niloticus Aust., a species which he found breeding in 
Pistia on the Nile. The 1st. to 4th. free abdominal segments 
bear long spines where the spiracles should occur. These 
at first sight appear to be breathing-tubes, but I cannot find 
that’they are open at the apex. Each abdominal segment in 
addition bears a row of fine spines of variable length near 
its posterior margin, which are longer on the dorsal side. 
The female aster is shown in Fig. 5. The male aster is 
narrower, the lateral spines are relatively longer, and the 
ventral region of the last segment is considerably inflated. 
In color the pupa is light leaf green, becoming nearly black 
before emergence, when the colors of the adult can be clearly 
seen through the integument. 
