HYMENOPTERA. 211 
stripes on the back, that in the middle bluish and those on the 
sides yellowish *. 
Those species, in which the antenne present but three very distinct 
joints, the last of which forms an elongated, prismatic, or cylindrical 
club, more slender, ciliated, and sometimes forked in the males; and 
where the two costal nervures of the superior wings are very remote 
from each other, constitute the subgenus 
Hyxotoma, Lat. Fab.—Cryrrtus, Jur. 
Some—Scuyzocera, Lat.; Cryptus, Leach, Lepel.—have four cu- 
bical cells, and the antenne forked in the males. The middle of the 
tibiz is destitute of spines +. 
Others—Hylotoma properly so called—similar to the preceding in 
their wings, have their antenne terminated in both sexes by a simple 
or undivided joint. Most of them—Hylotomes, Lepel.—have a spine 
in the middle of the four posterior tibiz. The larve or pseudo-cater- 
pillars have from eighteen to twenty feet. 
H. rose; Tenthredo rose, L.; Rees., Insect., II, Vesp., II. 
Four lines in length; head, top of the thorax, and exterior mar- 
gin of the superior wings, black; remainder of the body saffron- 
yellow ; tarsi annulated with black. 
The larva is yellow, dotted with black ; it gnaws the leaves of 
the Rose-tree. 
M. Lepeletier re-unites to the Cryptus, Leach, certain species which 
only differ from the preceding ones in the absence of spines on the 
middle of the four posterior tibiz. 
Other Hylotome, distinguished by the same negative character, 
but which have but three cubital cells, form his genus Ptilia ¢. 
Sometimes the antennze have at least nine very distinct joints, and 
do not terminate suddenly in a club. 
In some, and the greater number, the antennz, always simple in 
both sexes, or at least in the females, have fourteen joints at most, 
and commonly but nine. 
Tenturepo, Lat. Fab., 
Or Tenthredo proper, where the antennz consist of nine simple 
joints in both sexes. 
The larve have from eighteen to twenty-two feet. 
The number of dentations in the mandibles of the perfect Insect 
varies from two to four. The superior wings also differ in the num- 
ber of their radial and cubital cells. These characters have been 
* For the other species, see Oliv., Encyc. Méthod., article Cimbex; Fab.; Lat., 
Gen. Crust. et Insect., III, p. 227; Jurine, genus J'enthredo ; Panz., Hymen.; and 
the works already quoted. 
+ Leach, Zool. Miscell., III, p. 124; Lepel., Monog., Tenthred., p. 52. 
t Lepel., Ib., p.49. For the other species of Hylotome, see the same work, the 
preceding one of Dr. Leach, andthe Monograph of the various genera of this family 
by Kliig. 
