PENIS 57 



the abdomen, dorsal to the ventral arches of tlu' fifth and seventh 

 segments. It is composed of several sclerites. A median sclerite 

 (c.pe.), the anterior and ventral edge of which is rcjiighly semi- 

 circulai' in outline, forms the body of the penis. This is produced 

 laterally to form two alar processes ; at the bases of these processes 

 the lateral extremities of the dorsal arch of the eighth segment 

 articulate with the body of the penis ; the extremities of the pro- 

 cesses are attached to the lateral extremities of the ventral sclerites 

 of the seventh segment, the secondary- forceps. The penis proper 

 consists of a hollow cylindrical tube, the theca, which receives the 



cyoe.'-l 



Fig. 27. Penis seen from the right side after it has been removed from within the 

 terminal abdominal segments. 



i.rt/j. Inferior apophysis. «/i.;j. Theca of penis. p. rjl. Glans. s.a^. Superior 

 apophysis. Other lettering as in fig. 26, etc. 



ejaculatory duct. The theca articulates with the body of the penis 

 by means of a pair of small chitinous nodules ("cornetti" of 

 Berlese); posterior to the attachment the theca is constricted 

 slightly. Below the aperture of the entrance of the ejaculatory 

 duct, the theca is produced into a ventrally directed curved 

 process, the inferior apophysis (iap.) ; above the aperture a short 

 cylindrical process, the superior apophysis (s.ap.) arises. The 

 anterior end of the theca is continued as a slightly inflated hyaline 

 structure, the glans (p.gL), at the curved extremity of which the 

 ejaculatory duct opens. 



