THE PUPIPARA. 379 



stances, as the Scatophagce and SapromysKB; others, as 

 the OrtalidcB and Tephritidce, deposit their eggs upon 

 living vegetables and plants,, and thus produce excres- 

 cences like galls. The Dolichocerce live upon aquatic 

 plants ; Calobata has the power of walking upon the sur- 

 face of pools ; and the Actor ce frequent the sea-shores, 

 where they live upon fuci and marine rejectamenta. 



(341.) The sixth and last family of the Dipt era 

 contains the Pupipara. These have, for separative cha- 

 racters, antennae with hut one distinct joint, placed in 

 front of the lateral extremities of the head; and a mouth 

 without a proboscis, the function of which is executed by 

 two setae,, which form a sheath or tube. They constitute two 

 tribes, 1. The Coriacea; and, 2. The Phthiromya. The 

 first are distinguished by having a head of a moderate 

 size, and usually wings. We have before adverted to the 

 remarkable circumstance of their young undergoing its 

 states of larva and pupa within the abdomen of the 

 parent ; and as matured pupae they are born. They re- 

 semble the lice, living as parasites upon animals and 

 birds ; and although, when winged, they are not skilful 

 flyers, yet, in their native habitat, upon the skin of animals, 

 they have considerable activity, running about, but 

 chiefly laterally. Belonging to the first group, and 

 winged, we find Hippobosca, or the horse-fly; Strebla, 

 inhabiting the bat; Ornithobia and Ornithomya, upon a 

 variety of birds; and Anapera (Oocypterum Leach) and 

 Stenopteryx , exclusively upon swallows. Leptotena has 

 but rudimentary wings, and inhabits the deer ; and Mai- 

 lophaga, which is totally apterous, the sheep. The se- 

 cond tribe, the Phthiromya, contains but one genus, 

 Nycteribia animals whose situation is indicated as being 

 proximate to the Hippoboscidce, by the structure of their 

 mouth and the identity of transformations. These in- 

 sects greatly resemble spiders ; and thus indicate the con- 

 tiguity of the Arachnidce, although their structure is 

 completely analogous to that of the hexapod Insecta. A 

 particular detail of this would exceed the limits we are 

 restricted to ; and we shall therefore merely notice that 



