96 



I have one ^ , wholly black, Avhich measures only .19 in., 

 and which was found in sexual connection with a $ meas- 

 uring .33 in. ! ! ! and which answers in most respects to Say's 

 description of 0. vittata. I seldom find two in connection 

 which resemble each other in size or color ; and it ought to be 

 observed, that on account of the brevity of their existence, cop- 

 ulation seems to be their first object, so that one may observe 

 hundreds in that act. They run fast, but are easily captured. 

 I have an indistinct recollection that I formerly caught one in 

 the summer, but since the wild plum's blossoms are out, I have 

 not seen a single individual, although I have surveyed the 

 flowers of many other trees. 



I believe you wrote me in a former letter that you had the 

 $ of my 402 (^IlaUomenus ? ohliquatus Fabr. ?) and that the 

 fifth,^ sixth and seventh joints had a brush beneath. I have at 

 last found a male which corresponds entirely wdth your descrip- 

 tion. The antennas must at once distinguish that species from 

 my 721 [= ^'-Helo^js pimeUiis Fabr. teste Germ." Hentz's mss. 

 CataL], from which it differs chiefly in having the sixth joint 

 much smaller than the fifth and seventh. Notwithstanding the 

 difference in the scutel, etc., I had some doubts, which are now 

 entirely removed, about their forming two distinct species. 



I will give you an account of an insect which has puzzled me 

 more than any in all my entomological studies, — that coleopter- 

 ous insect which diff'uses a strong odor of spearmint, and is al- 

 ways found where that plant grows, in very wet ground, under 

 stones. I never found it in a dry place. I believe it must 

 belong to some osculant genus between the Carahidce and 

 Staphylinidce. It may certainly be said to have six palpi, as 

 many^ of the Carahidce. The external lobe of the maxilla, 

 which in the insects of that family assumes the form of an 

 additional palpus, is distinctly articulated in this with the 



1 The fourth has no brush beneath. 



2 I say many; because in many the lateral lobe is not much like a palpns. 



