228 Mr. E. Saunders' Sifiiopsis of 



thorax iDosteriorly, no yellow on the 3rcl segment of the abdomen, 

 and in having the 6th segment beneath raised into a small oval 

 tubercle on each side at the ai^ex, and in having the sagittae of the 

 armature toothed beneath. 



9 . Differs from vestalis in being smaller, with the vertex and 

 a band round the thorax posteriorly more or less yellow, in having 

 the basal segment of the abdomen more or less clothed with pale 

 hairs, the 3rd without any yellow at the apex ; apical segment 

 beneath more widely rounded, more shining, the edges more widely 

 reflexed, and without any velvety pubescence within them ; pos- 

 terior metatarsi decidedly narrower than the tibiee. 



Hah. Chobham, Norfolk, &c. ; probably widely dis- 

 tributed, but mixed with campestris in most collections. 



4. Psithyrus campestris, Panz. (PI. XII., fig. 1). 



Panz., Faun. Germ., 74, 11 ; Smith, Cat. Brit. Hym., 

 2nd ed., p. 223. 



A very variable species, especially in the 3" , which is 

 sometimes entirely clothed with black hairs, sometimes 

 almost entirely with yellowish hairs ; but, as far as I 

 know, the apical segments are never white. Perhaps 

 the most ordinary variety is that with the basal segment 

 of the abdomen clothed with yellowish hairs, the 2nd 

 and the centre of the 3rd at its base with black, and the 

 apical segments with yellow. The ? has a broad band 

 across the front and posterior portion of the thorax 

 yellow ; abdomen with an apical fringe to the basal seg- 

 ment, and the sides of the apical segments, yellow. The 

 following structural characters will serve to distinguish 

 this species from its allies in all its varieties : — 



(? . 3rd joint of the flagellum of the antennae sHghtly shorter 

 than the 2nd ; 4th about two-thirds as long as the 2nd and 3rd 

 together; 6th ventral segment simple, slightly channelled down 

 the middle, without apical elevations, each side bearing a long tuft 

 of black hairs ; genital armature with the sagittae largely dentate 

 beneath, the laciniae very broad and triangular, their inner margins 

 straight, meeting each other in parallel lines (see PI. XII., fig. 1). 



9 . Dorsal valve of Ctli segment narrowly pointed at the apex ; 

 ventral valve narrow and widely reflexed, and thickened at the 

 sides, causing a rather long apical sulcature between the elevations. 

 Length, 17—20 mm. 



Hah. Common and generally distributed. Lives with 

 Bumhiis hortorum and vais. 



