392 INSECTS OF MASSACHUSETTS. 



more than three quarters of an inch, exclusive of the horn on the 

 tail. This insect differs from the European Uroccrus Juvcncus 

 in the much greater brilliancy of its color, and in having shorter 

 antennae. The borer of this and of the preceding species resem- 

 bles, in form and structure, that of the pigeon Tremex, and is 

 used in the same way 



Urocerus abdominalis,* the black and the orange horn-tail, of 

 which only the male is known to me, has not been described be- 

 fore. It is black, with the four middle segments of the abdomen 

 deep orange. There is a pale yellow spot behind each eye ; the 

 front corners of the thorax are pale brownish yellow ; and there 

 are two minute yellowish scales on the back part of the thorax. 

 The abdomen is flattened and widened behind, and ends with a 

 flattened or triangular point. The antennae are long and tapering, 

 of a reddish brown color, with the two extremities black. The 

 wings are transparent, with brown veins, and are a little smoky at 

 the tips. The first four legs are ochre-yellow, with black thighs ; 

 and the hind-legs are black, with yellow knees and feet. This 

 insect varies in length from six tenths to more than three quarters 

 of an inch. It is found in July, on the trunks of the white pine. 



Mr. Westwood has ascertained that the grubs of the insects 

 belonging to the genus Xiphydria have the same form and habits 

 as those of the horn-tailed wood-wasps. The name comes from 

 a word signifying a small sword, in allusion to the borer of the 

 female, which is shorter than in the preceding horn-tails. The 

 winged insects have a rounded head, distant from the thorax, to 

 the lower part of which it is joined by a slender conical neck. 

 The body is nearly cylindrical, a little flattened, somewhat turned 

 up behind, and ends with an obtuse point. The antennae are 

 short, curved, and tapering at the end. 



Xiphydria albicornis of my " Catalogue," or the white-horned 

 Xiphydria, has white antennae with the two lowest joints black. 

 The head is black, with a narrow white line around each of the 

 eyes, forming a large oval, interrupted only in two places, on 

 each side of the head. The body is black, with a spot on the 



* So named from the great contrast in the colors of the abdomen. In my 

 " Catalogue " it stands under the genus Sircx of Linnaeus, which is the same as 

 Urocerus of Geoflroy. 



