BY FREDERICK A. A. SKUSE. 173 



simply give a very general description of its appearance. There 

 may be marked specific distinctions between the larvae of different 

 species. Mr. Krefft mentions that the larva found by him in Hyla 

 Citropus varied in structure considerably fi'oni all others. I must 

 postpone for the present a critical examination of the mouth-parts. 

 The living larva is pale lemon-yellow, very soft, glabrous, with the 

 skin pellucid ; elliptic-ovate, ll-segmented (including head), with 

 very indistinct stigmata ; head with two divaricate tentacles ; 

 posterior extremity of the body furcate. The posterior tentacles 

 evidently aid in progression. 



Pupa exhit iting the general appearance of the imago, entirely 

 enveloped in an extremely delicate transparent skin fitting glove- 

 like round the insect. Arista of the antennae overlapping the eyes 

 at the tip, directed sidewards. On the underside the wings reach 

 to about the posterior margin of the second abdominal segment, 

 but are separated from each other at the tips. Fore and inter- 

 mediate legs beginning at the shoulders (with the tibiae) running 

 between the wings, the fore tarsi reaching to a little above the 

 extremity of the wings, the intermediate terminating level with 

 the extremity. Tarsi of the hind-legs issuing from under the 

 wings just before the tip, almost touching at the tips, nearly 

 reaching the posterior margin of the fourth abdominal segment. 



Puparium exhibiting the general appearance of the larva, black, 

 opaque, with more or less distinct transverse wrinkles. 



Six species of Australian frogs at least are known to be subject 

 to the attacks of Batrachomyia, but at present it cannot be stated 

 definitely whether or no each species of frog harbours its own special 

 species of fly, though as both the flies now described were only 

 bred from particular frogs, it seems not at all improbable that this 

 will ultimately be found to be constantly the case with all species. 



The specimen in the Macleay collection named Batrachomyia 

 quadrilineata, belongs to the same species as an example reared 

 by me from PseudopJiryne Bibronii ; it is unfortunate that the 

 label of the former does not specify any particular frog. 



As far as observations go, the time of year at which the larvae 

 leave the frog is indefinite, and the duration of the several stages 



