2(57 



with one of Ihe al)ove-incnlionc'(l iiiai 



pores. Each spine is placed tlistally 



to the opening of a pore-chamber. The small intermediate spaces which are 

 generally (piadrangiilar or triangular may sometimes be almost slit-shaped, and 

 not rarely they are lacking between the 2 — 4 distal pore-chambers. This seems 

 lo be the rule in the ocrcia-bearing zoa^cia, and sometimes the two outermost of 

 the 4 distal pore-chambers are separateil from the innermost only by a slit- 

 shaped sinus (fig. 3). 



The vibracula which are [)laced on either side of the operculum and are 

 pailly immersed, have an ovale outline, and their frontal area shows a distal. 



?^^t^ 



V\i<. 1. Two zotrcin of Crcp. Poissoni Aiul., var. crinispiiia. X .'>5. 



2. A zoccciuin of the same form seen fi'om the basal wall, .-is in lig. 3 pore-chambers alternate 

 with intermediate spaces. X r)5." 



3. The distal part of a zocvcinm with ocecinm seen from the basal wall. X 55. 



4. An ancestrula of another variety of the same s])ecie.s. X 175. 



5. Operculum of Crep. Poissoni, var. erinispina. X 140. 



(i. The pro.ximal part of the flagellum of the same form. X 200. 



shorter, rounded subopercular area and a proximal, longer and narrower oper- 

 cular area. The flagellum (tig. (>) which is of about half the length of the zo(k- 

 ciuni is very thin, without teeth and in its proximal end provided with a biitlon- 

 .shaped expansion and a short conical cavity. Each vibraculum is in connection 

 with a marginal pore. 



