The additional discoidal cell will distinguish Diodontus from 

 Stigmus; and the more narrowed central submarginal one, as 

 well as the short petiole, at once separate it from Pemphre- 

 don. I should not, however, have detached it from tiie latter 

 o-enus if the trophi had been at all similar; but Pemphredon 

 has an undivided labrum, the mandibles are tvifid, and ihej^alpi 

 differently formed to those of Diodontus. 



One British species only has been recorded, to which I 

 have the pleasure of adding three others. 



1. D. gracilis Curt. Brit. Ent. j^l- 49G. c^. 



I took two males at Glanville's Wootton the middle of June, 

 and should have given them as that sex of the following species 

 if the insect supposed by Vander Linden and his friend M.Wes- 

 mael to be the male, did not so materially differ from my spe- 

 cimens. 



1^. D. insignis Vand. L. — Curt. 



Female 2 j lines ; black, basal joint of antennse beneath, a broad 

 stripe outside the mandibles and a spot on each side below the wings, 

 whitish ochre ; metathorax not strongly reticulated, striated at the 

 base and on a cordate space : wings slightly tinged with brown : legs 

 similar to D. gracilis ; but the anterior tibiae are entirely ochreous, 

 and the posterior are not bristly outside. 



2. D. minutus Fab. Ent. Syst. 2. 302. 32. 



Male 2 lines ; black, minutely punctured, lower part of face silvery; 

 palpi, underside of antennse (except at the base) and mandibles, pale 

 yellowish, excepting the tips which are ferruginous ; scapulars and a 

 spot below them yellowish white, the former with a brown spot ; 

 metathorax strongly reticulated, striated at the base; tips of thighs 

 ochreous, tibiae and tarsi of the same colour, the posterior tibial 

 brownish at the middle and the tips of the tarsi rather dark : wings 

 transparent. Female 2-^ lines ; black, mandibles as in the male, palpi 

 brown ; thorax the same ; abdomen stouter, ovate-conic, clothed with 

 very short ochreous pubescence ; tibiae, tarsi and tips of thighs ferru- 

 ginous-ochre with a piceous space on all the tibice at the middle, the 

 posterior having a few short spiny bristles outside : wings stained 

 pale brown, the 2nd submarginal cell trapezate. '' 



The 1st submarginal cell is shorter in this species than in 

 D. insignis, and the 2nd recurrent nervure is not united at the j| 

 middle of the posterior discoidal one, but beyond it. — July 3()th, ' 

 Black Gang Chine, Isle of Wight. 



3. D. pallipes Pa?iz. 52. 22. — tristis Vand. L. p. 76. 1. 



Female 2 to 2-J- lines, black, shining, minutely and sparingly punc- 

 tured, tips of mandibles castaneous, palpi brownish : metathorax 

 strongly reticulated ; wings with a brownish cloud across the middle, 

 the 2nd submarginal cell very much narrowed above ; tarsi brown, 

 palest at the base, anterior tibire sometimes of the same colour inside 

 towards the apex. 



Pallipes is not a well chosen name for this insect : never- 

 theless it ought to be retained. 



My specimens are, 1 believe, from Norfolk. The male I 

 have never seen. 



The Plant \^IIi/pcriciunpulchrum (Upright St. John's Wort). 



