The followino- letters denote the same parts in all the Plates. 



/'. Basal surface. /-'//. 



hr. c. Rranchijig ])eripheral canal system. /. /. 



c. Costie. /. 



c. c. Cavity of peripheral canals. in. 



e.g. — - genital organ. in. t. 



ciiib. Comb (swinnning plate). o. 



col. Colloblasts. or. 



c. tb. Cavity of tentacle-basis. o. f. 



cii. Cn])ule. 



c.z. Zone of cells, forming the cuimle. '''''■ 



r. Knibryo. ^^f- 



/•. c. Brood cavit\- for the embrN'o. P- J- 



re/. Ectoderm. f- 



cm/. Kndothelial lining (jf infun(lil)nlum. ■^'''"- ^■ 



rill. Kntodermal lining of genital or tentacular •^'- ^■ 



ca\'ity; Entoderm. spz. 



rp. Epidermis. .v/. /. 



r. .V. Entodermal sac. /. 



cxer. c. Excretory canal. /. /;. 



rxcr. n. — opening. /. o. 



/. Transverse furrow; "suboral" cri\it\-. /. ;•. 



g. (lenital organ. fr.r. 



gl. c. ("rland cells. /. sli. 



g.z. (ierminal zone. /.?. 



/. 1-Cctodcrnial in\a<'ination. 



Infundibulum. 

 Interstitial tissue. 

 Eumen of the "chimney". 

 Egg-membrane. 

 Mesodermal tissue. 

 Mouth-opening. 

 Oesophagus. 



Opening from the "suboral" cavity into the 



lumen of the "chimney". 



Ovary. 



Otolith. 



Polar field. 



.\pical sense organ. 



Secondary tentacle. 



Secondary mouth opening. 



Spermatozoa. 



vStomod:eal (phar\ngeal) folds. 



Tentacle. 



Tentacle-base. 



Oj^ening of tentacle-sheath. 



Tentacle-root. 



Transverse canal. 



Tentacle-sheath. 



Testis. 



