222 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



PLATE 12 



Fig. 1. Thalamoporella gothica (Busk), zooeciura, avicularium, cali- 

 per and compass. 



Fig. 2. Thalamoporella calif arnica (Levinsen), zooeciura, avicular- 

 ium and caliper. 



Fig. 3. Steganoporella cornuta new species. Details of ordinary 

 zooecium. 



Fig. 4. The same, "B zooecium," showing much larger aperture and 

 absence of spines. 



Fig. 5. The same, balsam mount of operculum with portion of at- 

 tached frontal membrane. 



Fig. 6. The same, operculum of "B zooecium" showing the heavy 

 supporting sclerites and toothed border. 



Fig. 7. Velumella americana Canu and Bassler, zooecium and avicul- 

 arian chamber. 



Fig. 8. The same, winged mandible of avicularium. 



Fig. 9. Cellaria diffusa Robertson. 



