BEES OF GREAT BRITAIN. 153 



3. Stelis octomacnlata. 



S. atra, punctulatissima ; abdouainis segmentis maculis lateral!- 

 bus flavis. 



Stelis octomaculata, Smith, ZooL iii. 1155. ?»$ ? - 

 Stelis ornatula, Nyland, Ap. Boreal Supp, p. 106 $ . 



Female. Length 3 lines. — Black ; head and thorax closely and 

 strongly punctured^ the face has a thin silvery-white pubes- 

 cence, the hinder margin of the vertex subemarginate. Thorax 

 shining, the wings fusco-hyaline, their apical mai'gins clouded; 

 the scutellum shghtly produced, subangular, pointed in the 

 middle. The abdomen shining, closely punctured, but not so 

 strongly as the head and thorax ; the basal segment has on 

 each side an ovate yellow macula, and the three following an 

 elongate-ovate stripe, pointed within ; the apex rotundate. 



Male, Length 3 lines. — Closely resembling the female, but 

 differing in having an ovate macula on the two basal segments 

 of the abdomen, the third has a narrow streak on each side, the 

 fourth two spots on each side, and the fifth a single spot. 



This species was bred from the nest of Osmia leucomelana 

 some years since by Mr. Thwaites ; at that time it was beheved 

 to be the Stelis minuta of St. Fargeau. Subsequently two fe- 

 males were taken by myself at Ilawley, Hants, and a single 

 male bred from a bramble-stick containing cocoons of Osmia 

 leucomelana-^ my specimens have been compared with those 

 taken by Mr. Thwaites, and proved to be the same species. 'In 

 order to ascertain with certainty whether the British species 

 was the Stelis minictay I obtained specimens of that insect from 

 the Continent^ and found the British species to be distinct. The 

 most obvious differences in the two species are the following : — 

 S. octomaculata has the hinder margin of the vertex nearly 

 straight; the scutellum is subangular, pointed in the middle 

 and shghtly produced; the insect is also coarsely punctured. 

 S, minuta has the vertex deeply emarginate its entire width; the 

 scutellum is rounded behind, and not produced; the insect is 

 much more finely punctured than S. octomaculata. 



Dr. Siehel of Paris obhgingly furnished the specimens for 

 comparison. 



h5 



