136 COLEOPTEEA. 



The following are the most striking peculiarities of the fam- 

 ily to which the blistering beetles belong. The head is broad 

 and nearly heart-shaped, and it is joined to the thorax by a 

 narrow neck. The antennas are rather long and tapering, 

 sometimes knotted in the middle, particularly in the males. 

 The thorax varies in form, but is generally much narrower 

 than the wing-covers. The latter are soft and flexible, more 

 or less bent down at the sides of the body, usually long and 

 narrow, sometimes short and overlapping on their inner 

 edges. The legs are long and slender ; the soles of the feet 

 are not broad, and are not cushioned beneath ; and the claws 

 are split to the bottom, or double, so that there appear to be 

 four claws to each foot. The body is quite soft, and when 

 handled, a yellowish fluid, of a disagreeable smell, comes out 

 of the joints. These beetles are timid insects, and when 

 alarmed they draw up their legs and feign themselves dead. 

 Nearly all of them have the power of raising blisters when 

 applied to the skin, and they retain it even when dead and 

 perfectly dry. It is chiefly this property that renders them 

 valuable to physicians. Four of our native Cantharides have 

 been thus successfully employed, and are found to be as pow- 

 erful in their effects as the imported species. For further 

 particulars relative to their use, the reader is referred to my 

 account of them published in 1824, in the first volume of 

 " The Boston Journal of Philosophy and the Arts," and in 

 the thirteenth volume of " The New England Medical and 

 Surgical Journal." 



Occasionally potato-vines are very much infested by two 

 or three kinds of Cantharides, swarms of which attack and 

 destroy the leaves during midsummer. One of these kinds 

 has thereby obtained the name of the potato-fly. It is the 

 Cantharis vittata,* or striped Cantharis. It is of a dull 

 tawny yellow or light yellowish-red color above, with two 



* Lytta vittaia, Fabricius. 16 



[ 16 The name Lytta is now adopted by most entomologists in preference to that 

 of Cantharis for these insects. — Lec] 



