190 



DISCOVERY REPORTS 



ALB. 



NU.CL 



IOO 



T 



NU.CL. 



NU.ALB. 



MUC 



ML/CD, 



d 



C.GEN: 



Fig- 13- 



Fig. 13. Limacina bulhnoides. Histology of the genital tract, (a) The albumen gland approaching the secretory condition at 

 stage 6. (b) The mucous gland at stage 5, before the onset of secretory activity, (c) The short glandular epithelium lining 

 the general cavity of the penial sac. (d) The prostatic epithelium, at stage 5, the cells opening into the prostate above, and 

 the smaller cells forming part of the external epithelial sheath below. 



ALB., albumen spherules beginning to pass from the free surface of the cell; M.F., muscle fibre in wall of penial sac; 

 MUC, mucous contents of a secretory cell of the mucous gland; NU.ALB., nucleus of albumen cell; NU.CL., nucleus of 

 ciliated cell; NU.EP., nucleus of glandular epithelial cell; NU.PR., nucleus of a prostatic cell; PR., Prostatic epithelium; 

 PR.EXT., external sheath of prostatic cells. 



Fig. 14. Limacina bulhnoides. Diagram of the relations of the gonad, genital ducts and penial sac, for comparison with Fig. 12. 

 The penial sac is shown in broken outline as it appears at stage 5; the receptaculum (REC.) in fact never appears until the 

 penis is lost, at stage 6. 



ALB., albumen gland; C.GEN., common genital aperture; FERT., fertilization pouch; GON., gonad; L.H.D., little 

 hermaphrodite duct; MUC. AC, accessory limb of the mucous gland; MUCD., descending limb of the mucous gland; 

 M.AP., male aperture; PE.S., penial sac; REC, receptaculum seminis; SEM.GR., ciliated seminal groove. 



