284 SYRPHID^. 



Genitalia in <S conspicuous, curved well under venter. Legs: 

 femora blade, with long, dense pubescence, which may be all 

 yellowish or all black. Tibine mainly black but indefinitely dull 

 reddish-brown basally and apically ; pubescence short, black ; 

 middle pair of tibiae rather irregularly shaped, ending (in cJ only) 

 in a slender, spine-like tooth; tarsi black or dark brown ; middle 

 metatarsi in cj^ with a pair of small black spines below, just 

 beyond base, and with several at tip ; 2nd tarsal joint with a few 

 apical spines. Wings yellowish-grey, pale brownish anteriorly; 

 veins black, all barely perceptibly, but broadly, brownisli-infuscated, 

 giving a slightly brownish tinge to the wing. Stigma a little 

 darker brown; alar squamae blackish, thoracic squamae yellowish- 

 grey, both pairs ^^ith yellowish fringe ; halteres yellow, clubs 

 black. 



Length, 17-20 mm. 



Described originally from a single $> from Onari, Garhwal 

 District, A¥. Himalayas, 11,000 ft., 21. vi. 1914 {Col. Tytler) and 

 redescribed more fullv from several of both sexes taken by Col. 

 Nurse in Kashmir, 8000-9000 ft., vi. 1901. Other specimens 

 seen from Andarbon, Garhwal District, 11,000 ft., vi. 1914. 



'^'VP^ ( $ ) i" Indian Museum. 



A very handsome species and the largest known in the East. 

 I am fully convinced that all the specimens referi'ed to represent 

 but a single species in spite of the considerable variation in colour 

 of the pubescence. The colour of the femoral pubescence does 

 not always agree with that of the abdomen: e.g., of two J d" 

 with mainly blackish abdominal pubescence, one has the femoral 

 pubescence also wholly black but the other has it all yellowish. 



Avery interesting case of double mimicry appears in connection 

 with this species. C. imitator itself closely resembles several 

 humble-bees of more or less common occurrence in the Himalayas, 

 and possesses the not unusual colour-pattern of a broad band of 

 dense, long yellowish pubescence on the anterior and hinder 

 thirds of the thorax, covering also the seutellum, and a similar 

 broad band on the basal third of the abdomen, the tip of the 

 latter being covered to a varying distance with dense bright 

 orange-red pubescence, and the remaining surface bearing wholly 

 black pubescence. Several humble-bees of South and Western 

 Europe, Sikkim, Tibet and the Himalayan Region generally, 

 possess this pattern of coloration. These are Bonihus vorticosus, 

 Gerst., distributed from South Europe to the Pamirs ; B.pi/ropy- 

 gus, Friese (variety of orientalis, Smith), from Sikkim; B.montanus, 

 Lep. (variety of alticoJa, Kris.), from Sikkim and Tibet ; and the 

 typical form of B. alticola itself from North and Western Eui'ope, 

 represented in the British Museum from Switzerland, Armenia 

 and Siberia amongst other localities. There is also a close resem- 

 blance between C. imitator and the Syrphid liy L>/C(tstris austeni, 

 sp. nov.* 



* Described in this voUiine, p. 279. 



