216 Mr. E. Saunders' Synopsis of 



(4) 1. Abdomen unspotted. 



(3) 2. Posterior margins of the first four abdominal seg- 

 ments pale . . . . . . . . . . . . aterrima. 



(2) 3. Posterior margins of segments not pale . . . . plicBoptera. 



(1) 4. Abdomen spotted at the sides . . . . . . octomaculata. 



1. Stelis aterrima, Panz. (PI. X., fig. 2). 



Panz., Faun. Germ., 56, 15 ; Smith, Cat. Brit. Hym., 

 2nd ed., p. 138. 



Black ; head and thorax closely punctured, dull. Abdomen 

 slightly shining, strongly punctured, the posterior margins of the 

 segments narrowly pale testaceous. 



(^ . Black ; head and thorax largely and rugosely punctured, 

 and clothed sparingly with gi'eyish hairs ; tegulae black ; wings 

 dusky, and with the anterior portion of the radial cell brown ; 

 scutellum with an angular tooth at the base on each side. Abdomen 

 slightly shining, sparingly clothed with short greyish hairs, largely 

 and deeply punctured, the posterior margins of the segments nar- 

 rowly pale testaceous ; 6th segment rounded at the apex ; 7th only 

 visible from the ventral side ; beneath with only the basal four 

 segments visible, the 2nd, 3rd, and 4th being densely fringed at the 

 apex with long golden hairs ; the 4th is visible only at its apex ; 

 the 5th and 6th are excavated on their ventral surface and clothed 

 with golden hairs ; the 8th is testaceous and produced at the apex 

 into two little round processes (for genitalia see PL X., fig. 2). 

 Legs clothed with short grey-brown hairs. 



5 . Almost exactly like the ^ , but the abdomen beneath 

 simple, showing the ordinary six segments, largely and irregularly 

 punctured, and sparsely clothed with golden brown hairs. Length, 

 8—9 mm. 



Hab. Not common. Hastings ; Southwold ; Deal ; 

 Weybridge ; Bircliwood, Kent ; Ilfracombe ; Sidmouth ; 

 Clifton, near Bristol ; Norwich ; Barham. F. Smith 

 says it is parasitic on Osmia fidvirentris, and probably 

 also on aurulenta ; is found sometimes in the flowers of 

 the mallow. 



2. Stelis phcBoptera, Kirb. 



Kirb., Mon. Ap. Angi., ii., p. 232 ; Smith, Cat. Brit. 

 Hym., 2nd ed., p. 139. 



Exceedingly like the preceding, but differs in both sexes by the 

 rather more shining thorax, its puncturation not being quite so 

 close on the disk as that of aterrima, and by the entu-ely black 

 abdomen, the apices of the segments of which are not discoloured 



