10 NOTES UPON THE GENERA SITONA, &C. 



The variation in the form of the rostrum is the first and most 

 important sexual character to be noticed. In the males it is 

 very generally shorter and thicker than in the females ; filiform, 

 sometimes attenuated, and often pubescent before the antennae ; 

 more generally glabrous, and, when compared with the females, 

 somewhat dull and obscure, or less glossy. The antennae of 

 the males are very generally seated at a greater distance from 

 the base of the rostrum than that of the females, but the distance 

 varies more or less. When the antennse are entirely testaceous 

 in the males, the club is black in the females. 



The rostrum of the females is longer, thinner, and more or 

 less attenuated, before the antennas — sometimes filiform, gene- 

 rally glossy and glabrous, — rarely pubescent. The antennae 

 are frequently seated nearer the base of the rostrum than in 

 the males ; but the distance is more or less variable. In pubes- 

 cent species, the males are more hairy than the females, and 

 the rostrum is pubescent before the antennse. With all due 

 deference and respect to the authority of so judicious and 

 skilful an entomologist as Mr. Kirby, I must venture to say, 

 that, at the commencement of his admirable monograph, it is 

 evident he was not so well acquaitited with the sexual charac- 

 ters ; but he evinces a more accurate knowledge towards its 

 conclusion. This is what might be expected of every person, 

 as he became better acquainted with the species — for example : 

 the characters which induced Mr. Kirby to separate A. rufi- 

 corne from A. Craccw, are entirely sexual. I must be allowed 

 to quote his own words : — " This little insect, {A. ruficorne) 

 although very nearly related to A. Craccw, is, I think, very 

 distinct from it. The hair on the body is thicker, the rostrum 

 has a shorter acumen, and it is covered, from the base to the 

 tip, with white hairs: the antennse, likewise, are entirely testa- 

 ceous." A. Craccw, A. Pomonct\ and A. suhidatuvi, the only 

 three species found in this country with subulated rostrums, 

 have all a strong analogy to each other in their sexual charac- 

 ters. The males of each species are more pubescent than the 

 females ; the rostrum, though subulated, is distinctly stouter in 

 the males before the antennse, than in the females, and co- 

 vered with pubescence. The rostrum of the females is not 

 so stout before the antennae as in the males : it is also more 

 attenuated, glabrous, and shining, than in that sex. There is 

 also a remarkable sexual character in A. Craccw, and a few 



