102 Dr. R. C. L. Perkins on Aculeate 



PALiEORHiZA, Pcrkins. 



In the males, apart from the clotliing of the terminal venti'al 

 abdominal segments and the carinations of the third segment, 

 a rather useful character is found in the shape of the apical 

 margin of the second segment beneath. This is distinctly 

 angulated in the middle in P. j)ervindis, reginanan, perkinsi, 

 &c., rounded or nearly straight in varicolor, parallela, tur- 

 neriana, &c. 



The seventh ventral segment furnishes useful characters : 

 this usually has the form of a pair of lateral processes or 

 wings on each side, one being dorsal to the other, the ventral 

 ones more chitinized and ciliated along the lateral margin. 



The genital armature is very similar in all the species 

 examined, the stipites simple, without lacinia or membrane, 

 with long hairs at the apices. In P. parallela, however, the 

 armature is very short, about as wide as long to the apex of 

 the stipites. In all the others it is elongate. In P. ehoracina 

 and P. parallela the very delicate inner (dorsal) membranous 

 wings are extremely minute and delicate, not so long as the 

 small ventral (more chitinized) triangular ones. In P. vari- 

 color i\\e,\ are more developed and appear more chitinized 

 and as long or longer than the upper, being also more pointed, 

 but are without the cilia in the latter. In perviridis the}' are 

 very long and twisted, extending far to the sides of the 

 dorsal ciliated ones. In basilura the finely ciliated wings are 

 butterfly-shaped, with black line at the base of the ciliae, and 

 I cannot detect any underlying membranous pair. 



I regret that I have no specimen of P. melanwa or P. denti- 

 cavda (which form a distinct section of the genus, with a 

 regular longitudinal rugosity of the anterior area of the 

 propodeum) for dissection. 



The seventh dorsal segment is emarginate apically in all 

 the species examined. Karely the genital armature is acci- 

 dentally a little protruded. Tliis is the case in the type of 

 P. dcnticauda, and the structures described do not belong 

 to naturally external jjarts. Similarly, in M. luduriosa the 

 description " apex of abdomen with a pair of minute con- 

 tiguous spines " refers to the tips of the sagittaj of the 

 genital armature. 



As to the females, P. ptrviridls (the male of ^\hich 

 has the angulated margin of the second ventral segment) 

 has the hind ealcar strongly toothed, but the species 

 Avhich I have identified as P. rariculor, tur)uriaiiu, and 

 tburacina (with simple second ventral segment in the male) 

 are without these teeth. Should the anaulated mar-iiu of 



