THE BIPTEBA. 



125 



cent. Such are the fire-flies, the cucuyo of the West 

 Indies, and the glow-worm. 



-^ A 



Fig. 159.— The early stages of tlie common House-fly. A, dorsal and B, side view 

 of the larva; a, air-tubes; s}>, spiracle. C, the spiracle enlarged. F, head of 

 the same larva, enlarged; bl, fabrum (?); md, mandibles; rnx, maxillEe; at, 

 anteonffi. _£', a terminal spiracle m^uch enlarged. D, puparium; sp^ spiracle. 

 All the figures much, enlarged. 



Order 13. Siphona2)tcra. — Fleas represent this group. 

 Order 14. Diptera. — The common house-fly (Fig. 159) 

 is a type of this gronp, all the members of which have hut 



Fio. 160. — Bot-fly of the ox and its larva. 



two wings, while the tongue is especially developed for lap- 

 ping lip liquids. The common house-fly lives one day in 



