XEMISTRIXIDJE. 61 



empodia developed pulvilliform, but, with the pulvilli often 

 minute. 



Throughout the world about one hundred species of this 

 family are known, the larger part of which are from South 

 America and Australia. Only six species are known from 

 North America and two or three from all Europe. Some of 

 the species have the wings with numerous cross-veins, almost 

 recticulate in appearance. Megistorhynchus longirostris from 

 Africa, though only about two-thirds of an inch in length has 

 a proboscis nearly three inches long. The flies are flower 

 flies, resembling in their habiis the Bombyliidse. 



But little is known of the larvae. The females of Hirmon- 

 eura obscura have been observed laying their eggs deeply 

 within the burrows of Anthaxia, a wood-boring insect, in the 

 pine rails of fences. The eggs were found in clusters and the 

 young larvae hatched from them differed very singularly from 

 those of a more mature growth. They are more slender, but 

 differ chiefly in having each of the abdominal segments from 

 the sixth to the twelfth provided with a pair of false legs 

 bearing a single elongate seta at the tip, the hooks pointing 

 backward ; on the thirteenth segment there are two pairs of 

 similar setae, the hooks of which, however, point forwards, 

 thus enabling the larva to attach itself firmly and raise itself 

 erect. These young larvae issued in great numbers from the 

 burrows in which they were hatched and, placing themselves 

 erect, were blown away by the wind. Here for a time they 

 have not been followed, but it is probable that they attach 

 themselves by the aid of the ventral hooks to the bodies of 

 large-sized beetles, by which they are carried into the ground 

 when the female enters to deposit her eggs. This is probable 

 from the fact that hundreds of pupae and pupa skins were 

 observed near the fence. On searching below these the larval 

 skins were found at a depth of about two inches and still 

 deeper were found the remains of the beetles, Rhizotrogus 

 solstitialis, in some instances with the larvae yet within them. 



