274 allan hancock pacific expeditions vol. 14 



Glossary 



Many of the terms used in the classification of the families, genera 

 and species will be found on pages 5-7 of Part I (Anasca), but there 

 are numerous others which apply only to the Ascophora. 



Anter. The portion of the primary aperture distal to the cardelles. 



Areolar pores. One or more rows of pores around the margin of the 

 zooecial front. 



Ascopore. A special median frontal pore opening into the compensa- 

 tion sac (q.v.) proximal to the aperture. 



Ascus. See compensation sac. 



Compensation sac. A chamber beneath the frontal wall for the adjust- 

 ment of internal pressure by permitting the entrance and exit of water 

 as the tentacles are protruded or withdrawn. 



Cardelles. Lateral hinge denticles to which the operculum is attached. 



Condyles. The same as cardelles. 



Costae, costal ridges. Rib-like ridges which arise between the areolar 

 pores and run inward on the frontal. 



Epitheca. The ectocyst or outer chitinous membrane. 



Frontal. The entire ventral area surrounding the aperture, but more 

 frequently applied to that part of it proximal to the aperture. 



Labium. A descending lip-like fold of the upper margin of the orifice 

 of the ovicell. 



Lyrula. A median denticle or shelf on the proximal border of the 

 primary aperture. 



Marginated. Bordered, as in the secondary fold around the base of 

 an ovicell. 



Multilaminar. Referring to a mode of zoarial growth in which new 

 layers of zooecia grow over and cover the older ones. 



Muscle attachments. The insertions of the occlusar muscles of the 

 operculum, sometimes at the border, sometimes at a distance from it, 

 frequently on the opercular sclerites. 



Olocyst. The primary calcified covering layer, usually thin but some- 

 times heavily calcified. (See pleurocyst and tremocyst.) 



Oral avicularia. Those definitely associated with the aperture, either 

 suboral or lateral-oral. 



Oral spines. Spines, usually jointed at the base, which develop on the 

 primary peristome. 



