Tachinidae. 51 



Also the way in which the parasite gets the air while in the 

 host is difTerent: 



1. The larva lives free in the host without connection with the 

 open air. Sarcophaginæ and perhaps Dexia rustica. 



2. The inbored larva goes into the host, and not till towards the 

 second stage or later it goes to the dermis or to a trachea and forms 

 here a hole (if with the mouth or with the posterior end is not known) ; 

 in connection with the hole a funnel is formed in which the larva is 

 placed. The funnel is formed by the host. 



3. The larva continues to be in connection with the air through 

 the hole formed by the boring in; also here a funnel is formed. 



The way in which the parasite pupates, in the host larva or 

 pupa, or outside, boring out of the larva or the pupa, the piaces where 

 it pupates and the way in which it hibernates is likewise manifoldly 

 varied; I have recorded the above, in order that by use of my book 

 one may get an idia of the very variated and interesting features in 

 the biology of these creatures, but for the rest I must refer to the 

 special works of Pantel, Thompson and others and especially to 

 the excellent account given by Baer (Zeitschr. f. angew. Entom. 

 VI, 1920, 185). 



In the above I have not considered the Oestrid forms, the sub- 

 families Hypoderm.inae^ Oestrinae and Gastrophilinae; these are 

 aberrating, but seem to be connected with the true Tachinids through 

 the foreign T achino-Oestridae YiWen. {Oestridae dubiosae B. B.); they 

 have no bristles at all on body and legs; the two first subfamilies 

 have a row or a bunch of hairs on hypopleura while Gastrophilus has 

 bare hypopleura. They are generally densely pilose. They are all 

 parasitic on mammals (our species on horse and ruminants). The 

 genus Cephenomyia, ranged under Calliphorinae., is of a similar aspect 

 and parasitic on deer. 



As seen from the description, the members of the family Tachi- 

 nidae will always be known with certainty. They are distinguished 

 from the Anthomijidæ, sole family with which they might be con- 

 fused, by several characters. The most distinctive character is the 

 row of bristles on hypopleura, only wanting in Gastrophilus, and 

 outside the Tachinidae only present in Eginia and Orygma which 

 for other reasons will be known as not belonging here. Next they are 

 characterised by the sternopleural bristles when three being placed 



in the position 2—1 or 1 — 1 — 1, while in the Anthomyids with three 



4* 



