140 PROC. ENT. SOC. WASH., VOL. 21, NO. 6, JUNE), 1919 



the cavity formed by the eighth tergite "S 1 " and the ninth sternite 

 "ha." Unfortunately, in removing the genitalia from the male 

 Oryssus loaned me by Mr. Rohwer, I did not realize the extreme 

 rarity of the males of these insects, and, due to the great diffi- 

 culty of handling the smooth segments which offer no means of 

 securing a firm hold with the forceps, my mind was so occupied 

 with removing the genitali intact, that I neglected to note which 

 side of the genital apparatus was uppermost when in situ. It 

 is a comparatively simple matter to identify that surface primi- 

 tively uppermost (i. e., not displaced by a torsion of the copula- 

 tory apparatus) in other sawflies, by comparing together the sur- 

 faces on which the copulatory ossicles ("gl," of all figures) are 

 located; but in the case of Oryssus the parts of the genitalia 

 (while suggestive of a relationship to Cephus, and also to Tremex) 

 are so different from those of other sawflies that it has been im- 

 possible to determine their homologies with any degree of ac- 

 curacy, although if I knew which side of the genital apparatus 

 is uppermost when in situ, it would greatly aid in determining 

 the homologies of the parts. The central structure "pv" of Figs. 

 37 and 38 evidently corresponds to the penis valves of other saw- 

 flies ("pv" of all figures); but I am unable to determine whether 

 the structure labeled "eg?" in Fig. 37 represents the copulatory 

 ossicle "gl" of Figs. 26, etc., of other sawflies (which is a strong 

 possibility), or the distal segment of the forceps "eg" of Figs. 

 13 and 26, or even the region labeled "pal," although I am in- 

 clined to interpret the structure in question in the manner indi- 

 cated by the label. The structure labeled "pal?" in Figs. 37 

 and 38 may represent the distal segment of the forceps labeled 

 "eg" in other figures, or the structure labeled "pal" in other 

 sawflies; but I am unable to determine which, from the material 

 available to me at present. From the foregoing discussion, it is 

 quite evident that the Oryssidae differ from other sawflies quite 

 markedly in regard to the parts of their genitalia (which, as a 

 rule, do not vary greatly in the sawfly group), as well as in other 

 anatomical details, and the peculiar character of the genitalia 

 and terminal segments of the Oryssidae might therefore be in- 

 terpreted as lending weight to the view that they constitute a 

 distinct suborder of the sawfly group. The importance one would 

 ascribe to such a small and highly modified group, however, is 

 largely a matter of personal preference. The lack of intermediate 

 forms has made it impossible to determine the closest affinities 

 of the oryssids among the members of the sawfly group, and the 

 genitalia offer no evident indications of a close relationship to 

 any of the forms here studied, although an examination of a wider 

 range of sawflies, may be more productive of results. 



