38 



BRITISH FLIES 



f5 



Fam. AsiLiD.E. Larva cylindrical, consisting of a head and eleven or twelve 

 body-segments. Head moderately broad, exserted, armed in front with stout teeth 

 (differing according to kind). Amphipneustic : the abdominal spiracles not terminal, 

 but placed dorsally on the penultimate segment (or on an area intercalated between 

 the last segment and tlie true penultimate). The middle segments of the body may 



m:^ 



>4M 



Fio. 65.— Larva of Thercva nohilUata. 



Fig. 66. — Laphria (?) larva. 



bear either circles of pseudopods, or areas intercalated on tlie ventral aspect 

 between two segments. The larvie are reputed to be either i)redaceous or to feed 

 on roots. That figured (fig. 66) was found in the burrows of coleopterous insects in 



a fir tree, and prol^aljly belongs to the genus 

 Laphria (cf. Brauer, pi. iv., figs. 60, 61, 63). 



Suborder : Cycloeehapha. Sectio Aschiza Becker. 



In the three families tiie pupa is coarctate 

 (cocoon-like), the final transformation occurring in 

 the skin of the larva. The head is to all appearance 

 wanting,* but is really present, though in the *S'//>'- 

 phid(if only revealed by dissection. 



Fam. Platypezid.e. Larva broad and depressed ; 

 from above appearing to have only nine or ten seg- 

 ments, but really consisting of a head and ten or 

 eleven segments, the head and the first following 

 segment being placed entirely on the under surface 

 (exserted ; that is, inferior, but not invaginated) : 

 the sides of the body with long outstanding bristles, 

 and sometimes deeply indented and serrate (Calli- 

 nijiia) (fig. G7). Amphipneustic, the posterior spir- 

 acles not, or but little prominent, rather widely 

 separated, placed at the base of the last segment ; 



anterior spiracles prominent on the prothoracic segment beneath the body. 



These peculiar larvte live in various kinds of agarics. For that of Platypeza see 



Bergenstamm, Verb. Z.-b. Ges. Wien., 20, 1870, p. 37, pi. 3. 



* Dr Perkins assures me that lie considers the larva of Pipunculm to be aceplialuus, as in J/usctdce. 



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\ 



Fig. 07. — Larva of Callimyia amcenu 

 seen dorsally. [After de Meijere 



