26 Mr. C. II. T. Townsend on Diptera 



colouring and closely similar form show tliat they all belong, 

 with one exception, to the same group. One of them possesses 

 no prescutellar row of bristles, and further differs in being 

 pronounced metallic green including head, with coppery on 

 abdomen and showing but little if any violet. It inclines 

 to the ohesa group. The others belong to the group of 

 V. amethystina, Bigot, which also includes comastes. Will., 

 chcetophora, Will., &c. To the last-named species I refer 

 one of the six above mentioned, while the other five are new. 

 These species may be distinguished by the following table. 

 They are all distinct from Volucella, n. sp. ?, Will., Synop. 

 p. 150. 



1. No prescutellar row of bristles present ; tliorax 



and scutellum bright metallic green ; abdomen 



coppery viridana, sp. n. 



Prescutellar row of bristles present ; metallic 

 colouring bluish, dark green, or violet 2. 



2. Wings hyaline, with only a milk tinge in oblique 



lights cJiO'topkora, Will. 



Wings strongly shaded with brown and 

 yellowish 3, 



3. Scutellum metallic, nearly or quite the colour of 



the thorax 4. 



Scutellum -wholly (dull or clear) brownish yellow, 

 contrasted in colour with the thorax ; face and 

 cheeks with stripes o. 



4. Face and cheeks witliout stripes, abdomen without 



yellow opalina, sp. n. 



Pace and cheeks with pronounced stripes ; 



abdomen yellow at base rafaelana, sp. n. 



6. Second abdominal segment in most part the same 

 colour as the scutellum ; rest of abdomen 

 without yellowish or with but a trace on 



anterior corners of third segment cordis, sp. n. 



Second and third abdominal segments same 

 colom- as scutellum in a nearly equal sub- 

 triangular patch on anterior corners, with a 

 smaller patch usually distinct on anterior 

 corners of fourth nautlana, sp. n. 



I have no specimens of amethystina, l^ig-5 ^^cl therefore do 

 not include it in the table. It is described by Bigot as 

 having the scutellum the same metallic violet as the thorax, 

 the cheeks with a stripe, but facial stripe apparently absent, 

 and with differences in the abdomen and wings which preclude 

 my referring any of the present species to it. It may be 

 added that all of these species have the second vein regular 

 and the margin of scutellum with bristles. 



28. Volucella clicetopliora^ Will. 



Two females, San Kafael, July 7 and 10. On flowers of 

 the Cordia sp. 



