1843.] Extract from Note Book regarding the Genus Paussus. 423 



rapid, I have never seen it moving but in a slow and sedate manner, at 

 which time the antennas are extended to the front of the head, and to 

 these is occasionally given an upward vibratory motion. What should 

 bring these insects in nearer conjunction with the genus Carabus is the 

 curious fact, that on being seized they emit from the anus a very acrid 

 liquid, accompanied by an explosion, and attended with a strong scent 

 resembling that produced by Brachini, and other allied genera when 

 similarly treated ; and although in minuter quantities, it is abundantly 

 sufficient to produce a very sensible heat, and the crepitation may be 

 distinctly heard and felt. Wherever the skin has been subjected to 

 its action, discoloration immediately ensues of a reddish brown color, 

 which soon after turns to a brownish black, resembling the stain pro- 

 duced by the touch of caustic, and which remains permanently fixed 

 for many days after. 



The explosion is occasionally repeated three or four times succes- 

 sively, at which periods a vapor may be observed to accompany each 

 crepitation, attended with a strong, and very penetrating odour, some- 

 thing like that of nitric acid. 



In one species I possess, the last segment of the abdomen is provided 

 with two large bundles of hairs, resembling densely set brushes, which 

 under the microscope are objects well worthy of examination ; each 

 hair appears like a fibre of golden-colored glass, and so closely are they 

 arranged, that it is only on being disturbed that their true character 

 can be discerned; yet notwithstanding the aid afforded by the move- 

 ment, the hairs composing this curious appendage are only so far 

 separable as to appear like a wetted painting brush. In another insect 

 of the same genus, and probably differing only from the above-men- 

 tioned one in sex, the abdomen beneath, near the penultimate segment, 

 is provided with two curved spines in addition to the hairy protu- 

 berance already noted. In a third, the posterior end of each elytra 

 gives support to a moveable incurved spine, projecting over the last 

 segment of the abdomen, and which when submitted to the microscope, 

 appears strongly accuminate, and somewhat in the form of the ex- 

 tremity of a scorpion's sting. 



In addition to these curious organs, several species are provided near 

 the exterior margin of the elytra, at the posterior extremity, with a 

 small papillaceous follicle, giving cover to an elongated appendage of 



