Phoridae. 85 



part of metathorax, and then behind it a larger posterior piece stretch- 

 ing from the anterior piece to near the hind margin of third abdominal 

 segment, but only including the dorsal halves of these segments; 

 this latter piece divides into two by a longitudinal median split. In 

 species of Paraspiniphora the way of opening is another; here a 

 dorsal plate is detached including metathorax, the two first abdominal 

 segments and the greater part of the third, the dividing line being a 

 little anterior to the hind margin of this segment, this plate is not 

 split in two; no front part is here detached; in Par. Bohemanni the 

 opening seems to take place in a way somewhat similar to that found 

 in Aphiochaeta, on the ventral side, however, only the head-segment 

 is separated off . — The larvæ mainly live in various decaying matters, 

 both vegetable and animal, and in fresli or decaying fungi; as to animal 

 matters species have been bred from dead insects, caterpillars, beetles 

 etc, from nests of wasps and from putrid snails, and they have also 

 been found on small vertebrates. All these species are not parasitical, 

 but some seem to be so such as Aphiochaeta juli on myriapods and the 

 species of Phalacrotophora (on Coccinellid pupæ, beetles and spider- 

 eggs, see under the genus), and Aphiochaeta ferruginea (= xanthina 

 Speiser) is recorded to cause myiasis in man, being able to develop in 

 the intestine; also some species living in nests of wasps and bees 

 seem to be parasitical as Hypocera incrassata^ and Aphiochaeta rata 

 is recorded as bred from larvæ present in a living Clerus jormicarius. 

 A curious case is recorded by Chappellier (Feuil. des jeunes Natura- 

 listes 43, 1913, 55) who found Phorid larvæ living in bodies of Canary 

 birds prepared with vapours of formaline; the larvæ pupated, but 

 were not bred, the pupæ were determined as belonging to A. riifipes 

 and Par. Bergenstammi (the latter determination I think dubious). 

 A not small number especially of exotic forms are myrmecophilous, 

 being either parasites or commensalists ; to the former belongs f . inst. 

 the American genus Apocephaliis of which the species A. Pergandei 

 "the ant-decapitating fly" lives as larva in the head of Camponotus 

 pennsylvanicus causing the head at last to drop off; among the latter 

 is the American species Metopina pachycondylae the larva of which 

 lives curled round the neck of the larva of Pachycondyla harpax being 

 fed by the workers together with the ant-larva; for many of the 

 myrmecophilous forms it is not known whether they are parasitical 

 or not. Some exotic species are termitophilous. — • As regards hiber- 

 nation this is in our climate generally passed in the pupal or some- 

 times in the larval stage, but many species have more than one brood 



