NO. 1 OSBURN : EASTERN PACIFIC BRYOZOA CHEILOSTOMATA 59 



3. Avicularia interzooecial 4 



Avicularia dependent, basal or lateral or both 5 



4. Avicularium associated with a kenozooecium Parellisina 



Avicularium normal, interzooecial Copidozoum 



5. Gymnocyst small, less than one-third of the front. . . Callopora 

 Gymnocyst extensive, one-half or more of front. . . Doryporella 



6. Ovicell closed by the operculum Membraniporidra 



Ovicell closed by a special membrane 7 



7. Avicularia and spines wanting Mollia 



Avicularia and spines present 8 



8. Avicularia interzooecial, with rounded or spatulate mandible ; 



fenestrae usually present between the zooecia. . . Retevirgula 

 Avicularia dependent, basal or lateral or both 9 



9. Spines present, basal avicularium covers front or ovicell (except 



in T. magnipora) Tegella 



No spines; dorsal wall with white punctuations. . . Bidenkapia 



Genus ALDERINA Norman, 1903 



The front wall is entirely membranous, side walls crenulated; no 

 spines, but nodular processes sometimes present ; no avicularia. Dietellae 

 present. Ovicell usually bearing a rib or depressed area. Genotype, Mem- 

 branipora imbellis Hincks, 1880 :275. 



Alderina smitti new name 

 Plate 6, fig. 2 



Membranipora irregularis, Smitt, 1873:8 (not d'Orbigny, 1839:17). 

 Alderina irregularis, Canu and Bassler, 1928 :27. 

 Alderina irregularis, Hastings, 1930 :708. 

 Alderina irregularis, Osburn, 1940 :363 ; 1947 :13. 



It has been recognized for a long time (see Canu and Bassler, 1920: 

 142) that Smitt's M. irregularis is not that of d'Orbigny and a new name 

 should be given it. It seems proper that it should be named after the 

 great Swedish bryozoologist who described and figured it carefully. 



Zoarium encrusting on stones, shells and corallines. Zooecia of mod- 

 erate size, 0.45 to 0.55 mm long by about 0.35 mm wide; gymnocyst 

 small, usually wanting, cryptocyst broad, descending, without horizontal 

 lamina, continuing on the sides rather broadly to the operculum, the 

 margin crenulated. The opesia is ovate and narrowed at the level of the 

 operculum which has a brown bordering sclerite. Dietellae present. No 

 spines, no avicularia. 



The ovicell is prominent, thick walled, not closed by the operculum, 

 0.26 mm wide. 



