PROC. ENT. SOC. WASH., VOL. 21, NO. 6, JUNE, 1919 143 



paratus occurs) ; but I doubt that this feature will be found to 

 hold good in attempting to differentiate between the two types, 

 if the torsion of the genital apparatus should prove to have any 

 meaning from the standpoint of the study of the interrelationships 

 of the members of the sawfly group or their mating habits. This, 

 and similar question of the affinities of the sawflies can best be 

 taken up by specialists in these groups, or by those having ac- 

 cess to a wide range of types, so that the present paper is intended 

 merely to furnish a basis for the more intensive study of the 

 different types of genitalia and terminal structures present in 

 the sawfly group, and to attempt to determine the meaning and 

 homologies of the parts met with in the terminal structures of 

 these insects. 



Mr. S. A. Rohwer has made a preliminary study of the genital 

 apparatus of the males of sawflies based largely upon the genitalia 

 of Tremex, and he has very kindly permitted me to include in 

 the present paper his table of the parts of the genitalia (for which 

 he has adopted the terminology employed by other workers in 

 this group) in order that the different views as to the homologies 

 of the parts may be here discussed, in an effort to determine the 

 correct interpretation of the parts, and the designations which 

 should be applied to them. Mr. Rohwer's views of the nature 

 of the genital apparatus, which he considers to be made up of 

 three parts, are briefly set forth in the following table: 



Third Gonapophyses Forcipes 



Cochlearium (Claspers of authors, 

 aussere Haltezange of 



(Outer pair of appendages Enslin, 1912) 



Of the ninth sternite) 



Stipes 



Cardo 



First Gonapophyses Praeputium I Sagittae of authors, ( Praeputium 



(Paired appendages of the < innere Haltezang 



eighth sternite) [ of Enslin, 1912 [ Manubria 



Second Gonapophyses Penis 



(Inner pair of appendages 

 of the ninth sternite) 



Mr. Rohwer informs me that Hartig, 1837, applies the term 

 "manubria" to the processes labeled "pa" in Fig. i ; while the 

 basal portion of these processes (i. e., the plates labeled "pa" in 

 Figs. 4, 5, etc.), together with the copulatory ossicles "gl" of 

 Fig. 14, and the sclerites labeled "pal" in Fig. 14, constitute the 

 structures designated as the "praeputium" by Rohwer, 1912 (pp. 

 215-217). The "third gonapophyses" or "forcipes" mentioned 

 in the table given above, are the gonopods "gb" and "eg" of the 



