The following letters denote the same parts in all the Plates. 



/'. Rasal surface. 



hr. c. Branching peripheral canal system. 



c. Costfc. 



c. c. Ca\'it\' of peripheral canals. 

 (•.,.<'. — - genital organ. 



ciiib. Comb (swimming ])late). 



Cdl. Colloblasts. 



(■.//'. Cavity of tentacle-basis. 



cit. Cnjnile. 



c.z. Zone of cells, forming the cupule. 



c. Embryo. 



r. c. Brood ca\ity for the embr\'o. 



ret. Kctoderm. 



iiid. Endothelial lining of infundibulum. 



rut. Entodermal lining of genital or tentacular 



cavity; Entoderm. 



rp. Epidermis. 



r. s. Entodermal sac. 



rxcr. r. Excretory.' canal. 

 fxcr. o. — opening. 



/ Transverse furrow; ".suboral" ca\ity. 



g. Genital organ. 



gl. r. Gland cells. 



g. z. Germinal zone. 



/. Ectodermal invagination. 



in. 



in. t. 



n. 



inf. Infundibulum. 

 /. /. Interstitial tissue. 

 /. Lumen of the "chimney". 

 Egg-membrane. 

 Mesodermal tissue. 

 IMouth-opening. 

 or. Oesophagus. 

 o. f. Opening from the "suboral" cavity into the 

 lumen of the "chimney". 

 nv. Ovar\'. 

 ot. Otolith. 

 p. J. Polar field. 



.V. Apical sense organ. 

 .SVC. t. Secondary tentacle. 

 .V. o. vSecondary mouth opening, 

 ■v/:. Spermatozoa. 

 st. f. Stomodfeal (pharyngeal) folds. 



t. Tentacle. 

 /. t). Tentacle-base. 

 /. (I. Opening of tentacle-sheath. 

 /. ;•. Tentacle-root. 

 //•. c. Transverse canal. 

 /. aV/. Tentacle-sheath, 

 /.v. Testis. 



