[ 172 ] 



hooks, one series pointing backward, the other forward. The rounded contour 

 of the first segment is broken by the slightly projecting anterior spiracles, 

 which are directed laterally Outward. Posteriorly the puparium narrows 

 distinctly into a short tubular portion which terminates in two bifurcated 

 lobes, the post-abdominal spiracles. In the intersegmental space which 

 separates the first and second abdominal segments are a pair of holes situated 

 on the latero-dorsal side. 



In a future paper we hope to deal with certain gaps in the foregoing 

 account of the life history and to give a description of the structure and habits 

 of the adult fly. 



ACKNOWLEDGMENT. 



We desire specially to express our thanks to Dr D. Keilin, of the Quick 

 Laboratory, who has generously placed his extensive knowledge of the litera- 

 ture at our disposal, and also been most helpful with friendly criticism and 

 suggestions. We have further found his recent work on the life-history and 

 larval anatomy of Melinda cognata Meigen, parasitic in the snail Helicella 

 (1919), of much assistance in determining the morphological details of the 

 various larval stages. 



REFERENCES. 



Cholodkowsky, N. (1884). Uber eine am Tracheensysteme von Carabus vorkommende 



Tachina-ATt. Zool. Anzeig. vil. 316-318. 

 DuFOUK, L. (1827). M^moire pour servir a Thistoire du genre Ocyptera. Ann. d. Sci. Nat. 



X. 248. 

 Keeun, D. (1919). Life history and larval Anatomy of Melinda cognata Meig. parasitic in 



Helicella virgata, Da Costa, etc. Parasitology, xi. 4.30. 

 Knuth, p. Handbook of Flower Pollination. English Translation, Oxford. Vol. in. 1909. 

 ■KuNKEL d'Herculais (1879). Observations sur les moeurs et metamorphoses du Oymno- 



soma roturtdatum, Linn. Ann. Soc. Eni. Fr. v. s6r., ix. 349. 

 Meade, R. (1891). Generic characters of Siphona genus. Ent. Month. Mag. xxvii. 126. 

 Nielsen, J. C. (1909). Jagttagelser over Entoparasitiske Muscidelarver los Arthropoder. 



Entomol. Meddelelser, 2 R. iv. pp. 28^2. 



— (1918). Tachin-Studier. Vidensk. Medd. fra Dansk natvrhist. Foren. lxix. 247-262. 

 Pantel, J. (1898). Le Thrixion Halidayanum Rond., essai monographique sur les caract^res 



ext^rieurs, la biologie et I'anatomie d'une larve parasite du groupe de Tachinaires. 

 La Cellule, xv. 290. 



— (1909). Recherches sur les Dipt^res a larves entomobies. La Celhde, xxvi. 173. 

 Rennie, J. (1912). Note upon a Tachinid Parasite (Bucentes geniculata de Geer) of Tipula 



sp. Proc. Roy. Phys. Soc. Edin. xvni. 231. 

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d'une Tachinide k un bote aquatique dipt^re; un nouveau cas d'ectoparasitisme interne. 



C. R. Acad. Sci. cxlii. 1348. 

 ScHiNEE, J. R. (1862). Fauna Austriaca. Die Fliegen, Wien, pt i. 520-52L 

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