ZOOLOGY 



SECT. 



capsules occur similar to those of the Ccelenterata, but these 

 seem to be derived from Hydra, Cordylophora, and other Coelen- 

 terates, which form their food. Adhesive cells with processes also 

 frequently occur in the epidermis. Beneath the epidermis is a 

 basement membrane (b. m.), which in the Polycladida is of a thick 

 resistant character, and contains stellate cells. 



In a small number of the Trematoda three layers are distin- 

 guishable in the integument a homogeneous, or nearly homo- 



FIG. 209. Caryophyllaeus. 

 d. g. vitelline duct ; d. st. vi- 

 telline glands ; e. excretory 

 pore ; k. mobile organ : od. 

 oviduct ; or. germarium ; p. 

 cirrus ; r. s. receptaculum se- 

 minis ; t. lobes of testes ; v. d. 

 vas deferens ; v. s. vesicula 

 seminalis ; w.g.o. female aper- 

 ture. (After Leuckart.) 



FIG. 210. Gyrocotyle (Amphiptyches). 



eo. excretory opening ; mo. male open- 

 ing ; n. longitudinal nerve ; n'. anterior 

 nerve-ring ; n. r. posterior nerve-ring ; o. 

 opening of uterus ; o. ovary ; o'. recepta- 

 culum ovorum ; p. base of cirrus ; r.s. re- 

 ceptaculum seminis ; r. s. o. opening of 

 vagina ; *. sucker ; t. testes ; ut. uterus ; 

 r. 8. vesicula seminalis ; yk. vitelline 

 glands. (After Spencer.) 



FIG. 211. 

 Archigetes. 



(After Leuckart. 



geneous, outer cuticle ; a cellular, or at least nucleated, epidermis, 

 and a basement membrane ; but the cellular epidermal layer is 

 absent as such in the adult condition in the majority of the Trema- 

 todes, and there is only a homogeneous, non-nucleated outer layer, 

 which may be the modified epidermis, or may be the cuticle, with 

 or without a basement membrane. Rhabdite-forming and other 



