14 NOTES UPON THE GENERA SITONA, &C. 



graph, by the accession of several specimens, this insect is 

 better described ; and Mr. Kirby does not seem to have the 

 least suspicion that it is the A. /oveolatum, or at all like it, but 

 links it in affinity, and next to, A. Spartii, a very different 

 insect. 



1 must again refer to my series of this species, {A. Spencii) 

 of both sexes, and to Mr. Kirby's. A. foveolatum, being the 

 first described, and a male insect, according to the rigid rules 

 of nomenclature, should stand ; and it is a good specific name. 

 A. Spencii, a female insect, is unfortunately described after- 

 wards, but in the same monograph. 1 shall, therefore, retain 

 the latter name in my cabinet, as a *' tribute, justly due to one 

 of the most acute and learned entomologists of this island." 

 A. striatum is the female of^. immune ; and No. Si, A. immune, 

 is the male of the former. This is a truly Protean species ; it 

 varies very considerably in the form of the thorax and elytra : 

 the longitudinal furrow on the thorax of both sexes is present 

 in my Yorkshire specimens, and absent in the males only, of 

 those taken in the south. There are two insects in Mr. 

 Ingall's collection, one of which, at first, appeared to me to be 

 a distinct species, and allied to A. immune ; since which I have 

 seen other specimens in the collection of the Entomological 

 Club, and another in Mr. Ingall's, which lead me to a suspi- 

 cion that it may turn out a singular variety of A. immune. My 

 great aversion to create new species from single examples, es- 

 pecially when allied to an exceedingly variable one ; and the 

 want of a long series of varieties from the London habitats 

 of A. Pisi and A. immune, imposes upon me silence for the 

 present. I captured numbers of this species from the Ulea: 

 Europwus, on warm days in February last, and I experienced no 

 difficulty in identifying the sexes of many pairs of the same ; the 

 form of the rostrum, and the situation of the antennee thereon, 

 in both sexes, so much resemble each other, that it requires 

 some little practical experience to separate them by the eye. 



No. 32. A. virens, S^fhn. ; No. 33, A. marchicum, 33 mas. 

 Mr. Kirby says, '* this little insect {A. marchicimi) is so simi- 

 lar to the one before it, that I suspect it may be only a 

 sexual variety. The principal difference lies in the thick- 

 ness and shortness of the rostrum." The first is a female, 

 and the second a male : I have taken them repeatedly in 

 coitu, and, from their well-defined sexual characters, I have 



