46 



basal joints (ecape) of the antennae. If so, this larva had a some- 

 what elongate scape, intermediate between the usual short form and 

 the hypertrophied scape, such as still exists in the larva of Synlestes. 



The thorax of the larva AB is only poorly outlined, but a small 

 piece at w pressed obliquely down upon it appears to represent a 

 wing-sheath. A little further back, to the right, lie the remains of 

 the right hind-leg (p), showing clearly the femur, tibia, and a small 

 piece of the tarsus. Below this, and apparently detached from the 

 rest of the specimen, lie the last six segments of the abdomen, and 

 two of the caudal gills (g). The anterior abdominal segments, very 

 flattened out, appear to be just indicated to the right of the detached 

 portion. The latter is only visible in iSpec. 20, lying above the 

 letter B. 



One of the caudal gills has its outline fairly well shown (g above 

 B) and a portion of the chitin at its base is still preserved. The gill 

 is elongate-lamellar with a well-rounded tip, and appears to belong 

 undoubtedly to the Lestid type of gill. 



The second specimen is represented by CD. The head lies 

 sideways just below C. It is badly crushed and partly lost. Part 

 of the chitin of the eyes and labial mask is still visible. The thorax 

 of this larva is overlain by that of the other, and the two cannot be 

 definitely distinguished. But the posterior half of the abdomen is 

 clearly visible, projecting obliquely downwards in both Specs. 20a 

 and 206. The gills in this specimen are better preserved than in 

 AB, the outlines of the two of them being very distinct. A large 

 part of the chitin at the base of one. and a small piece at the tip of 

 the other, are still clearly visible. 



There can be little doubt that these larvae belong to the Lestidse, 

 and differ very little from those of the present day. As the Lestidse 

 are chiefly represented in Australia by the large genus Austrolestes, 

 the name AUSTROLESTIDION DUARING/E is proposed for the two 

 specimens under discussion. 



TYPES : Specs. 20a and 206 (counterparts) (Plate 1, fig. 6). 

 (B. D. Coll.) 



SUMMARY OF DUARINGA RESULTS. 



The discovery of the fossil larvae above described is in no way 

 remarkable, in view of the admitted antiquity of the Lestidaa. The 

 most interesting point about the fossils (if the above interpretation 

 of the parts be correct) is the greater length of the scape of the 

 antennae compared with that of recent larvae (with the exception 

 of Synlestes). This bears out the generally accepted belief that, in 

 the Odonata, the antennae have undergone progressive reduction in 



