110 INSECTS OF MASSACHUSETTS. 



room-beetles, flat bark-beetles, and the like, with which they 

 for ma large and distinct section of Coleopterous insects. The 

 following are the most striking peculiarities of the family 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 

 antennae 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 powerful in their effects as the imported spe- 

 cies. For further particulars relative to their use, the reader is 

 referred to my account of them published in 1S24, 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 Cant'iaris vittata*, 

 or striped Cantharis. It is of a dull tawny yellow or light yel- 

 lowish red color above, with two black spots on the head, and 

 two black stripes on the thorax and on each of the wing-covers. 

 The under-side of the body, the legs, and the antennae are black, 

 and covered with a grayish down. Its length is from five to six 



Lytta vittata, Fabricius. 



