240 Mr. E. Saunders' Synoims of 



11. Bomhiis sylvaruin, Linn. (PL XII., fig. 11). 



Linn., Faun. Suec.,«cl. alt., p. 425; Smith, Cat. Brit. 

 Hym., 2nd ed., p. 203. 



Black, clothed with greyish hairs, an indefinite band across the 

 thorax between the wings, and a very narrow band at the base of 

 the 3rd segment of the abdomen, clothed with black, the 4th and 

 following segments with red or yellowish red. 



3' . Head clothed with greyish hairs, intermixed with black on 

 the vertex and at the sides ; cheeks shining, remotely punctured, 

 about as long as their apical margin ; mandibles piceous at the 

 apex. Antennae wdth the 4th joint of the flagellum equal to the 

 2nd and 3rd taken together, the 2nd slightly longer than the 3rd, 

 the remaining joints subarcuate. Thorax clothed with grey hairs, 

 with a wide indefinite band of black hairs across the centre ; wings 

 slightly dusky. Abdomen clothed with gi-eyish hairs at the base, 

 the 2nd segment with ochreous hairs at the base and with grey at 

 the apex, the 3rd with black hairs at the base and grey at the apex, 

 and the following segments with yellowish red hairs ; each with a 

 narrow apical band of grey hairs; beneath entirely clothed with 

 grey ; genital armature with the sagittae curved at the base, the 

 apex hamate beneath ; squama produced at the base inwardly into 

 a long curved spine ; lacinia triangularly produced beyond the 

 squama, obliquely truncate on its inner margin, which is armed 

 with a small square tooth, and produced slightly at both angles 

 (see PI. XII., fig. 11). Legs clothed with grey hairs; tarsi piceous 

 at the apex, clothed with ferruginous hairs. 



2 and 5 . Like the $ in colour, but differing in the usual sexual 

 characters, and also in having the 2nd segment of the abdomen 

 often with black hairs intermixed with the grey. Length, <? and 

 ? 14— 16 mm., 12 — 14 mm. 



Hah. Generally distributed. 



The coloration of this species, which varies very little, 

 will distinguish it from any other, except perhaps the ^ 

 of the rare j^omonim ; but from that, its 3" may be known 

 at once by the shorter face, the form of the genital 

 armature, and the narrow black band at the base of the 

 3rd segment of the abdomen. On the Continent a 

 nearly black form occurs, var. nigrescens, Perez, but I 

 have seen nothing of the kind from this country. 



