Ghrysotoxum. 569 



it is flat below, much arched above, of a dirty brownish colour, 

 otherwise it resembles the contracted larva. The pupa of C. festivum 

 answers rather well to Beling's description; the mentioned filaments 

 are still seen as low warts, arranged as usual; those on the sides 

 at the posterior end are the largest; there are no anterior spiracular 

 tubes; the pupa has the posterior end curved strongly downwards ; 

 the length is 10 mm. 



The species of Ghrysotoxum are very beautiful files, characterised 

 by the yellow bovvs on abdomen; they occur in woods and fens and 

 on meadows, sometimes at the horders of water, and they are seen 

 on many various flowers. 



Of the genus 20 species are known from the palæarctic region; 

 5 occur in Denmark. 



Tahle of Species. 



1. Third joint of antennæ nearly as long as, or longer than 



the two basal joints together; wings without any blotch 2. 



— Third joint of antennæ distinctly shorter than the two basal 

 joints together; wings with a larger or smaller blotch at 



the anterior margin after the middle 3. 



2. Eyes with short, whitish hairs ; second antennal joint longer 

 than first; venter with three pairs of yellow spots at the 

 front margins of the segments; male genitalia very large; 



rather large species 1 . cautum. 



— Eyes with longer, denser, dark hairs ; second antennal joint 

 as long as first; venter with only two pairs of small, yellow 

 spots on third and fourth segments, lying in the middle; 



male genitalia small ; smaller species 2. arcuatum. 



3. Abdomen with four yellow bows 4, 



— Abdomen with only two yellow bows 5. hicinctum. 



4. All femora quite yellow 3. festivum. 



— Anterior femora black at the base 4. vernale. 



1. C. cautum Harr. 



1777. Harr. Expos. engl. Ins. 60, PL XV, fig. 15 {Musca). — 1901. 

 Verr. Brit. FL VIII, 643, 1, figs. 441—442. — 1907. Kat palaarkt. Dipt. III, 

 146. — C. scutellatum Macq. 1827. Soc. Se. Lille, 349, 4 et 1834. Suit. å 

 Buff. I, 490, 4. — 1838. Meig. Syst. Beschr. VII, 107, 10. — C. sylvarum 

 Meig. 1822. 1. c. III, 171, 6. — 1856. Loew, Verh. zool. hot. Geseli. V^ien, 

 VI, 609, 2. — 1862. Schin. F. A. 1, 253. 



Male. Vertex black, frons black, shining, greyish white pruinose 

 at the sides, with a middle longitudinal impression in front; epistoma 

 yellow with a black middle stripe and a black band from the lower 

 anterior corner of the eye down to the mouth; vertex and frons 

 black-haired, epistoma with erect, yellow hairs except on the middle 



