18 ERNEST WARRFJN. 



{c.e.c.) wliifh form a portion of the ectoderm epitlielium liiimg the 

 gonophore. 



Fig. 20. — x 180. Transverse section of gonophore. showing spadix 

 (up.) and tlie mass of spermatocytes (spcy.). 



FiCr. 27. — X 180. Vertical tangential section of gonophore. showing 

 endoderm diverticula in transverse section {e. rl). the thin ectoderm 

 epithelium {er.ep.), the mass of spermatozoa {spz.), and the clusters of 

 I'ipe spermatozoa (>•. sp.) in which tails have been formed. 



Fig. 28. — X 18* >. Empty gonophore-case; the spermatozoa have been 

 dischai-ged through the gelatinised u^jper portion (>^u\pr.). The swell- 

 ing up of this portion of the perisarc apparently arises through the 

 action of the ectoderm cap-cells (cf . <?.2>., figs. 24, 26). 



Explanatory References. 



c. PC. Elongated connecting ectoderm cells between ectoderm linnig 

 the sporosac and endodermal diverticulum. CVe. Coelenteron. 



</. Diatoms and other debris. fZ.p. " Deckenplatte " or ectodermal 

 cap-cells. 



e. c. Ectodermal chamber, e. cy. Empty calyx-cavity, f . </. Endo- 

 dermal diverticulum, f. ep. Endodermal epithelium lining ccelenteron. 

 ('. p/'. Endodermal projection, e. sp. Empty sporosac. e. c. c. Endo- 

 dermal vacuolated cells, ec'-p. Ectoderm lining sporosac. en. Endo- 

 derm. 



/. Thin floor of perisarc of hydrorhiza. f-}^''- Firm perisarc. 



g. Genital cells in ectoderm of sporosac. g. o. c. Glandular oral 

 endoderm. 



in. Mouth, m.c.t. Muscvilar ectoderm of tentacle. 



H. Nematocyst. n.s.e. i. Non-septate endodermal axis of tentacle. 



o. e. c. Opening of ectodermal chamlier to exterior. 



l>. Supporting vertical pillar of perisarc in hydrorhiza. 



/■. Perisarc roof of hydrorhiza. ;•. o. t. Ridge of older tentacle on 

 calyx, r. .sj). Clump of ripe spermatozoa with tails, t'.y-f- Ridge of 

 younger tentacle on calyx. 



s.e.t. Septate endoderm of tentacle, s.pr. Soft perisarc. s.pr.t. 

 Soft pei-isarc on upper surface of tentacle, s. n\ Sea-weed. sp. Spadix 

 of gonophore. s/'fy/. Spermatocytes, sw.pr. Swollen perisarc. spz. 

 Spermatozoa. 



