40 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



Genus TERMINOFLUSTRA Silen, 1941 



Avicularia squared and situated at the bifurcations of zooecial rows ; 

 ooecia endozooecial, embedded in the bases of the succeeding zooecia. 

 Genotype, Flustra barleei Busk, 1860 :120. 



Terminoflustra membranaceo-truncata (Smitt), 1867 

 Plate 3, fig. 10 

 Flustra membranaceo-truncata Smitt, 1867 :358. 

 Flustra membranaceo-truncata, Robertson, 1905 :292. 

 Flustra membranaceo-truncata, O'Donoghue, 1923 :24; 1926:47. 



The zoarium is erect and consists of irregularly flabellate fronds, 

 unilaminar and thin. The zooecia are irregularly quadrate or elongate- 

 hexagonal, truncate at both ends, usually narrower at the proximal end. 

 The walls are thin, with a minute spine, often wanting, at each distal 

 corner. The avicularia, which are rather rare, are usually situated at the 

 bases of new rows of zooecia; nearly square in outline and about one- 

 third as large as the zooecia; the mandible is semicircular, directed distal- 

 ly, with a continuous chitinized border. 



Ooecia endozooecial, embedded in the bases of the succeeding zooecia, 

 small, inconspicuous except in transmitted light. 



Circumpolar. Robertson recorded it from the Pribilof Islands, Bering 

 Sea; O'Donoghue listed it from Banks Island and China Hat, in British 

 Columbia waters. 



In studying the material from the U. S. Alaska Crab Investigation, 

 I find two small colonies from Alitak Bay, Alaska, at 30 fms. 



Family Hincksinidae Canu and Bassler, 1927 

 This family includes membranipores of simple structure, similar to the 

 Membraniporidae except for the presence of an endozooecial ovicell. The 

 ovicell is usually a narrow, transverse, shallow structure, opening widely 

 into the zooecial cavity and closed by the operculum, but sometimes it is 

 merely a rounded expansion of the zooecial cavity into the base of the 

 succeeding zooecium. Spines, avicularia, and dietellae may be present. 



Key TO Genera of Hincksinidae 



1. No avicularia, no dietellae Aplousina 



One or both of these present 2 



2. Tall pedunculate avicularia among the spines. . . Cauloramphus 

 Avicularia sessile, vicarious 3 



3. Avicularia usually paired at the proximal corners, cryptocyst 



strongly developed Antropora 



