484 



ZOOLOGY 



SECT. 



Such a brood-pouch is formed in certain Phanerocephala by the 

 raising up of the integument on the ventral surface. In some 

 species of Polynoe and allied genera, the fertilised ova and the 



ov 



Fig. 370.— Spirorbis laevis, a hermaphrodite tubieolous Polychset. Lateral view of entire 

 anim il. ant. neph. anterior nophridium ; br. branchiaj ; as. oesophagus ; o/>. operculum with 

 developing embryos in its interior ; ov. ova ; sp. sperms ; st. stomach. (After Claparede.) 



resulting embryos adhere in masses to the dorsal surface under the 

 shelter of the elytra ; in some other Polycha^ta they are stuck by 

 means of some viscid secretion all over the dorsal surface, or 

 they may adhere singly to the ventral cirri. In certain Crypto- 



