(Wytsman Gen. Ins. Hem. p. 6), to a form of which I have 

 referred above as occurring on the ninth segment in the 

 Eupitheciina . The hairs are variously arranged and there 

 may also be present large spatulate spines (Ochyria 

 quadrifasdaria, pi. xlm.). 



I now proceed to consider the internal part which con- 

 stitutes the sexual organ, remarking that the central area is 

 extremely complex, and that in some cases it is very diffi- 

 cult to allocate the various parts on any uniform system. 

 The central organ is The Penis, which emerges from a 

 circular cone, The Anellus. This cone is attached laterally 

 to the costal fold of the valvulee, dorsally to the transtilla, 

 and ventrally to the base of the valvae. In the Geometrida 

 the penis is retractile and is attached to the edge of the 

 anellus by a membraneous tube, The Manica. The anellus 

 is subject to great modification, and bears organs to which 

 I have given distinctive names as a helpful aid in 

 differentiation. 



THE PENIS. 



As this name has been given to various parts by 

 different writers, I think it advisable to state definitely 

 that the penis is the whole central organ. 



It consists of : (i) The sfldceayus, a strong tube or 

 trough which is kept in position in the centre of the tegu- 

 men by means of the manica. (ii) The Manica, a sleeve- 

 shaped eversible membraneous tube surrounding the 

 aedceagus. (ii) The Anellus, the funnel-like cone from 

 which the sedoeagus protrudes, (iv) The Vesica, which 

 with its armature The Cornuti. is extruded into the bursa 

 of the female during copulation, (v) The Ductus Ejacu- 

 latorius, which, entering the aedceagus just above its blind 

 end, runs throughout its length, and is continued in un- 

 broken connection with the vesica, the two together form- 

 ing the seminal duct. 



