10 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



into the frontal membrane." He included in the Division the families 

 Aeteidae, Bicellariidae, Farciminariidae, Scrupocellariidae, Flustridae, 

 Membraniporidae, and Cribrilinidae. It is quite evident that Levinsen 

 included too wide a range of anascan forms within the division and Har- 

 mer later (1926) removed all but Levinsen's "Membraniporidae" and 

 "Flustridae" to other divisions and arranged them in the following 

 manner: 



Division I. Inovicellata JuUien, 1888, Family Aeteidae. 



II. Malacostega Levinsen, 1909, Membraniporidae, Flustri- 

 dae and their allies. 



III. Coilostega Levinsen, 1909, the Opesulidae of JuUien and 

 related families. 



IV. Pseudostega Levinsen, 1909, Cellariidae. 



V. Cellularina Smitt, 1867, Scrupocellariidae, Bicellariel- 

 lidae and related forms. 

 VI. Cribrimorpha Harmer, 1926, Cribrilinidae. 

 This arrangement has generally been accepted by later authors. 

 Still more recently Silen (1942:56), has set up another arrangement 

 of the anascan groups, and introduced two new "sections." It is quite 

 possible that his system may be nearer the truth, but as all of the species 

 dealt with in this report fall within the scope of Harmer's system, that 

 arrangement will be followed. 



Division I INOVICELLATA Jullien, 1888 



The zoarium is creeping, adnate and stolon-like. At intervals there 

 are swollen, spindle-shaped enlargements, from each of which rises an 

 erect zooecial tube with an operculum like a minute trap-door at the 

 upper end. The zooecium consists of both the erect tube and the basal 

 enlargement, as the polypide extends into both of them. There are no 

 avicularia, vibracula, spines, nor permanent ovicells, though temporary 

 membranous ovicells may be present until the eggs have undergone at 

 least a part of the larval development. Polypide regeneration may occur, 

 in which case a new "head" with a new operculum extends beyond the 

 primary zooecial tube. One family and one genus in this Division. 



