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



and is clearly the corresponding dorsal region (tergite) of the 

 ninth sternite "ha." 



The sternite "ha" (Figs. 46, 49, 55, 56, etc.), situated below 

 the male genitalia has been referred to as the hypandrium in all 

 insects (Cramp ton, 191 8 a and 191813), regardless of whether it 

 represents of the sternum of the eighth, ninth, or other abdominal 

 segment. It is incorrectly referred to as the hypopygium in 

 some insects; but this term always refers to the entire male 

 genitalia, etc., in Diptera, or to the plate immediately below the 

 anus (i. e., the ventral plate of the terminal segment labeled "ep" 

 in Fig. 55, etc.) in other insects, so that in order to avoid ambiguity, 

 the more appropriate designation hypandrium has been retained 

 in the present paper for the plate labeled "ha," situated below 

 the male genitalia. 



The apparent tenth tergite labeled "ep" in Figs. 49, 54, etc., 

 probably represents the united tenth and eleventh tergites of 

 lower insects. It frequently bears the small appendages "c" 

 homologous with the cerci (Figs. 46, 54, etc.) and is situated 

 above the anal opening "a" of Figs. 46, 50, 54, etc. The region 

 below the anal opening is sometimes chitinized to form a subanal 

 plate or hypoproct, while the supraanal plate "ep" is referred to 

 as the epiprocl, in lower insects. In the Mecoptera, the entire 

 region through which the anus "a" opens, including the epi- 

 proct "ep" (Fig. 50) and hypoproct, is called the anal pappilla 

 or proctiger. 



The supraanal plate or epiproct "ep" of Fig. 54, tends to unite 

 with the tergite of the ninth segment "9*;" and in many sawflies, 

 both are overlapped by the eighth abdominal tergum. In Oryssus 

 (Fig. 42) not only the ninth and tenth tergites, but the genitalia 

 also are retracted beneath, and are completely concealed by, 

 the tergum of the eighth (and the sternum of the ninth) abdominal 

 segment. Except in a few cases, however, such as that of Oryssus, 

 mentioned above, the male genitalia are at least partially visible 

 from the exterior. 



The copulatory apparatus of the male, is typically composed 

 of a basal ring, "gg" (Figs, i, 27, 41, etc.) which bears a pair of 

 genital forceps or claspers, each of whose arms is composed of a 

 basal segment "gb" and distal segment "eg" (Figs. 27, 41, etc.). 

 A pair of copulatory ossicles "gl" becomes differentiated from the 

 basal segments of the forceps "gb" (Figs. 14, 17, 40, etc.), and be- 

 side them there usually occurs a larger sclerite "pal" which is 

 also probably a demarked portion of the basal segments of the 

 genital forceps. On the opposite side of the "genitalia" there some- 

 times occurs a pair of processes "pa" (Figs, i, 2 3, etc.), which 



