some neto Species of Drawida. 523 



The spermiducal gland, or the prostatCj is a large pyriform 

 organ sessile on the body-wall, its vertical axis being twice 

 or slightly more than twice its antero-posterior diameter. 

 In some specimens the glandular part with its club-shaped 

 cells is really confined to the eutal and ectal divisions, while 

 the rest of the wall is composed of a few muscle-fibres and 

 cubical epithelial cells, thus converting the glandular struc- 

 ture into a vesicle in which the sperm-duct lies in several 

 coils. The atrial papillae are comparatively small. 



There is an ovarian chamber, i. e. segment 11 remains 

 closed on opening the worm, though sometimes the sides 

 may rupture on stretching the animal. The ovisac, which 

 looks rather like the pistil of the pea, protudes from this 

 chamber into segments 12 to 14. The ovary is enclosed in 

 the sacs, which lie over or oq the sides of the first two 

 gizzards. There is no oviduct, but the side-walls of the 

 ovarian chamber approximate so as to form separate ovarian 

 conduits. The female aperture is small in all the forms 

 investigated. 



The spermathecal ampulhie (PI. XV. fig. 3 c) are lodged in 

 depressions on the posterior face of the fat septum 7/8, and 

 are completely hidden by the equally thickened posterior 

 septum. Sometimes the depressions for the lodgement are 

 absent. The two ampullje are close together, being separated 

 only by the dorsal vessel. In shape they are subspherical and 

 are whitish-looking. In the teased preparations the contents 

 were only a coagulated albuminous mass easily dissolved by 

 alcohol and acetic acid. The microscopic structure of the 

 ampulla is identical with that of the similar structure of 

 D. somavarpatna. The spermathecal duct is fairly thick 

 and lies in a few coils iu the large cavity of somite 8, and 

 penetrates the septum 7 1'S at the base, and follows the some- 

 what tortuous course in the hinder part of somite 7. It 

 enters the atrial pouch at its apex, which it fairly deeply 

 pitted. The vesicle is a large, strongly muscular, pear- 

 shaped gland fixed to the body-wall by the narrow end. It 

 lies fore and aft to the long axis of the body. The sides 

 of septum Qj7 are greatly hollowed out for the reception of 

 these glands, in which the duct opens out into a large sac. 

 In the fully mature forms the atrial pouch looks like a 

 barrel with spiral hoops of muscle-bands, which form a con- 

 spicuous external feature. The glandular portion in such a 

 case is confined to tlie two ends of tlie organ. The cavity 

 of the vesicle is composed of a lining membrane (PI. XVIIi. 

 fig. 10</), whose cells are much larger than than those of the 

 duct, and by their greatly irregular arrangement give rise to 



