MONOGRAPH OF THK NORTH AMERICAN PROCTOTRYPID.E. 15 



with the iutenml walls of the abdomen, their tips beiu^- sharply pointed, 

 ueetlle-like, and usnally mieioscopically serrated. The spicuhTO are 

 used for i)iereinj^ or borinjj;-, and move forward and backward ou the 

 upper plate as a saw in the hands of a carpenter. 



Figs. 7 and 8 represent the terebra of Epyrix grandis, one of the 

 hirgest species in our fauna. The different paits are lettered identi- 

 cally as iu i'. e<ii(d((tH.s. Here the tube (or outer sheaths conjoined) 

 (nJis) is short and conical, and is the form most commonly met with in 

 the family. 



At rig-. two cross sections of the ovipositor proper are shown — A 

 from ueai- the; base, B from nearer the apex, the breadth and thickness 

 varying slightly in accordance with the tapering of the ovipositor. 

 The transverse diameter of tiie upper plate averages about 0.042"^'" ; 

 of the basal plates or spicuhe, 0.015""", while vertically they average 

 0.018'"'" iu diameter. 



It will be seen that the structure of this cross-se»tion agrees fairly 

 well with others that have been mad(; of the terebrant llymenoptera, 

 the only real dilference being the nuich larger canals through the 

 center of the three pieces and the small additional canal in the lower 

 inner angle of the spicula*. 



All the canals have apparently a membranous lining, and unless they 

 have something to do with the control of the ovipositor their function 

 is not apparent. 



MALE GENITALIA. 



It takes so much time to thoroughly study the organs of generation, 

 on account of their minute size, in most groups of the llymenoptera 

 Parasitica, besides the almost absolute certainty of the destruction of 

 valuable specimens, that most entomologists are content to depend 

 upon external characters for the recognition of species, and conse- 

 quently comparatively little is known of the male genitalia in any 

 family composing this section, although there can be no doubt as to 

 the specific and classiflcatory value these organs possess. 



In order to give some idea of these organs in the Proctotypidie, on 

 PI. I, I have figured the male genitalia of three different si)ecies. 



Fig. 10 represents the male genitalia of Epyris carbonari us: A, the 

 parts viewed from above; p, penis or penal sheath, strongly exserted, 

 iu outline narrow, harp shaped, although strongly flattened like a leaf, 

 bilobed at apex, the lobes with rouiuled margins; at the middle (o) is a 

 longitudinal slit or opening, the orifice for the fleshy penis. On each 

 side of the penis, attached to a swollen lobe at base, are two horny 

 sheaths, a pair on each side, that nuiy be termed respectively the upper 

 and lower sheaths; us is the upper sheath. In this species it is slender 

 and gradually acuminate, or lanceolate; ?,s is the lower sheath; it is 

 much larger, broader, and more rounded at apex, although it is here 

 divided by a longitudinal slit into two more or less distinct points, each 



