152 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 65. 



Fig. 7.— Syngenodrilus lamu- 

 ENsis. Wax model of pros- 

 tate GLAND RECONSTRUCTED 

 FROM SECTIONS, POSTERIOR 



VIEW. X75. pp, Narrowed 



PART EXTENDING TO SURFACE 

 or BODY AT PROSTATE PORE. 



In the sections a rather small gland, which is assumed to be a pros- 

 tate gland, is attached to the ventral body wall at a position slightly 

 laterad of h in each of somites 11, 12, and 13 (fig 3). Each gland 

 consists of a tubular glandular part of which the lumen is some- 

 what contorted and which ends in a very short duct having a length 



about equal to the combined thickness of the 

 hypodermis and circular muscle layer of the 

 body wall (fig. 7). The lumen of the wider 

 glandular part is bounded by an epithelial 

 layer, associated with a thicker glandular 

 layer which is surrounded by a thin, appar- 

 ently muscular layer, bounded superficially 

 by a very thin epithelium recognizable only 

 in favorable situations. Presumably these 

 glands are in pairs. 



The ovaries are rather extensive structures 

 in the anterior part of 13 and the oviducal 

 fuimels are wide and lead into very short 

 ducts (fig. 3) which open to the exterior at 

 13/14, slightly laterad of seta line 5. The 

 ovisacs have already been mentioned. They 

 inclose the dorsal sperm sacs and extend 

 posteriad of 22 (fig. 6). The ova correspond closely in size and 

 granular contents with those of other Moniligastridae. They are 

 about 0.045 mm. in diameter. 



There is a pair of spermathecae in each of somites 8 and 9. Each 

 spermatheca includes a duct and a long tubular sac and there are no 

 spermathecal glands nor 

 atrial chambers such as are 

 found in some of the 

 species of Moniligaster and 

 Drawida. The spermathe- 

 cae resemble rather those 

 of the primitive genus 

 Desmog aster. The duct of 

 the sectioned spermatheca 

 of 9 is about 1.5 mm. long 

 and but 0.07-0.1 mm. in 

 diameter in the greater 

 part of its length. The 

 septum 8/9 follows the 

 duct rather closely, forming a tubular chamber open toward the 

 posterior (fig. 8). The saccular glandular part is somewhat longer 

 than the duct and about 0.35 mm. in diameter, with a lumen of which 

 the diameter is about one-third as great (fig. 3). A compact mass 

 of spermatozoa extends throughout the greater part of the lumen of 





% /y^j^^^ 



i,y^ V--: 



"«-\ I, 



-^f^ >ji V Sf^^^' si 



Fig. 8.— Stngenodrilus lamuensis. Semidiagrammatic 

 longitudinal section through spermathecal duct 

 and investing septum, 8/9. x35. si d, speemathecai. 



duct; St p, SPERMATHECAL PORE. 



