267 



with one of the above-mentioned marginal pores. Each spine is placed distally 

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

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

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

 to be the rule in the ocecia-bearing zooecia, and sometimes the two outermost of 

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

 shaped sinus (fig. 3). 



The vibracula which are placed on either side of the operculum and are 

 partly immersed, have an ovate outline, and their frontal area shows a distal. 



Fig. 1. Two zooecia of Crep. Poissoni Aud., var. crinispina. X 55. 

 - 2. A zooEcium of the same form seen from the basal svall. As in fig. 3 pore-chambers alternate 

 with intermediate spaces. X 55. 



3. The distal part of a zooecium with ooecium seen from the basal wall. X 55. 



4. An ancestrula of another variety of the same species. X 175. 



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



6. The proximal 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 (fig. 6) which is of about half the length of the zooe- 

 cium is very thin, without teeth and in its proximal end provided with a button- 

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

 with a marginal pore. 



