210 INSECTA. 



approximated and pai-allel, without a wide intermediate sulcus, form 

 the genus 



CiJiBEx, Oliv. Fab. — Crabro, Geoff. 



The larvae have but twenty-two feet. Some of them when irritated 

 spurt a greenish liquor from the sides of their body to the distance 

 of a foot. 



Dr. Leach *, by having recourse to the number of joints anterior 

 to the club, their relative proportions and the arrangement of the 

 cells of the wings, has divided the genus Cimbex into several others, 

 one of which, Perga f, is peculiar to New Holland, and is distin- 

 guished from all the others by the following characters. The four 

 posterior tibiae have a movable spine on the middle of their inferior 

 side. The scutcUum is large and square, with its posterior angles 

 projecting in the form of teeth. The valves that sheath the ovipositor 

 are covered externally with numerous short and frizzled hairs. The 

 antennae are very short, and have six joints, the last of which, or the 

 club, is without any vestiges of annuUi as in Syzygonia, a genus 

 established by Kliig on some species from Brazil +. The radial cell 

 is appendiculated, and there are four cubital cells, the second and 

 third of which receive, each, a recurrent nervure — the transverse 

 nervures of the disk. 



M. Lepeletier de St. Fargeau, in an excellent Monograph of the 

 TenthredinetBP, only adopts the genus Perga, and in conjunction with 

 him we will consider those of the English naturalist as simple divi- 

 sions of Cimbex. 



The two following species belong to that number in which the 

 antennse have five joints before before the club. 



C.lutea; Tenthredo lutea,L.; De Geer, Insect., II, xxxiii, 

 8 — 16. About an inch in length; brown; antennse yellow; 

 abdomen yellow, with violet-black bands. 



The larva, or pseudo-caterpillar, is of a deep yellow, with a 

 blue stripe, edged with black along the back. On the Willow, 

 Birch, &G. 



C. femorata ; Tenthredo femorala, Lat.; De Geer, Insect., II, 

 xxxiv, 1 — 6. Large; black; antennse and ovipositor of a brown- 

 yellow; blackish-brown spots on the posterior margin of the 

 superior wings; posterior thighs very large, in one of the sexes 

 at least. 



The larva lives also on the Willow ; it is green, with three 



* Zool. Miscel., Ill, p. 100, et seq. 



f Ibid., 116, cxlviii; Lepel., Monog. Tenthred., p. 40. 



+ Monog. Entom., p. 177 ; in the same work, p. 171, he gives the characters of 

 another genus Pachglosficfa, also peculiar to Brazil. The antennae consist of five 

 joints. The superior wings are dilated near their extremity, and the callous point is 

 semilunar. The second, third, and fourth joints of the posterior tarsi are very short. 

 He mentions three species. 



The genus Perga, on account of the cells of the wings and the spines of the pos- 

 terior tibia, should come directly before Hylotoma. 



