OESTRUS. 269 



Head depressed. Face transverse, vertical, slightly impressed, ciliated 

 on each side; clypeus projecting. Peristoma large. Eyes elliptical, 

 transverse. Arista pubescent. Prcebrachial and anal areolets small, 

 complete. Abdomen conical, with seven segments; second segment very 



36. nasica, Hal. A. N. H. iii. 411 (1839). Cinerea, fronte tho- 

 raceque ferruginosis, facie albida, tarsis basi ferrugineis. Long. 1^ ; 

 alar. 2-i lin. 



Grey. Front and thorax somewhat ferruginous. Face whitish. 

 Tarsi ferruginous at the base. 



Rare. In Mr. Haliday's collection. (E.) 



FAMILY XXVIII. (ESTEID^E. 



CESTRID.E, Leach, (Estrid. Ins. (1817); Curt.; Steph. ; Westw. (Es- 

 tracidce, Meig. Automata, Dumeril. (Estrides, Blanch. 



Caput sat magnum. Proboscis obsoleta. Alee completes. Vena cubitalis 



simplex. Halteres manifesti. 



Head pretty large. Proboscis obsolete. Wings complete ; cubital vein 

 simple. Halteres uncovered. 



The flies of this family are usually called Bots; they deposit 

 their eggs on cattle, and their Iarva3 are nourished in the bodies 

 of these animals. 



r very large. Prse- 0' oinin S the ti P of tlie cubital ' L CBs 8 - 

 Alulee brachial vem (.joining the cubital before its tip 2. CEPHALEMYIA. 



very small ............. 3. GASTEROPHILUS. 



Genus I. CESTRUS. 



CESTRUS p., L. ; F. ; Schr. ; Gmel. ; Latr. ; Lea. ; Clark, L. T. ; Fal. ; 

 Meig. ; Mcq. Hypoderma, Clark, (Estr. ; Mcq. ; Guer. CEdemagena, 

 Clark, QBstr. ; Mcq. ; Guer. ; Blanch. Cephonemyia, Mcq. 



Corpus sublineare, pilosum. Caput thorace paullo angustius. Frons 

 magna, antice latior. Facies brevis, lata, concava, carinata. An- 

 tennae brevissimse. Ala mediocres ; vena costalis ala multo brevior; 

 prcebracliialis cubitali ad apicem juncta ; discalis transversa undulata. 

 Alulae maxima. Abdomen ovatum, thorace sequale, subtus concavum 

 et retractum. Pedes sat longi et validi; ungues et onychia sub- 

 elongata. 



