700 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



zoarial characters. Some of these have proved to belong in other families 

 and others placed in synonymy until only two genera, Lichenopora 

 Def ranee, 1823, and Disporella Gray, 1848, have survived the research 

 of later authors. Most recent authors have used only Lichenopora, but 

 Borg, 1944:234-5 and 249, has given what appear to be good reasons 

 for the retention of Disporella. Borg even goes so far as to propose a 

 new family, Disporellidae, to include only this genus, but this appears 

 to me to be unwarranted on the basis of the characters, 



A few citations will indicate the difficulty others have had : "One 

 cannot help feeling despair when trying to determine the Lichenoporae." 

 (Waters, 1889:282) ; "The determination of the species of Lichenopora 

 is admittedly very difficult." (Harmer, 1915:160) ; "The determination 

 of the species, even the recent ones, presents much difficulty." (Canu 

 and Bassler, 1920:812) ; "The discrimination of the species . . . has 

 scarcely but begun." (Borg, 1944:213). 



Family Lichenoporidae Smitt, 1866 



Zoaria rounded or ovate, occasionally otherwise modified in outline 

 by the nature of the substratum ; more or less convex, sometimes dome- 

 shaped ; attached the full width of the basal lamina, or the basal lamina 

 free and turned upward at the edge, or, when on small stems, they may 

 be attached by a short central stipe of variable width. The central part 

 of the zoarium, varying in size with the species, is occupied by cancelli 

 (alveoli, Borg), and outside of this area the functional zooecia are 

 arranged in radiating series or more or less in quincunx. The "peri- 

 stomes" are usually much higher next to the central area and decrease 

 in height regularly to the margin ; usually the basal lamina extends in 

 a thin rim around the outer edge. Zoarial budding occurs in some 

 species, either vertically or near the edge, and sometimes very complex 

 zoaria may be formed in this manner. The ovicells are brood-chambers 

 of considerable size, occupying the central area, branching out in lobes 

 between the rays, or located entirely between the rays ; covered by a 

 thin calcified layer with minute pores, which may be obscured by the 

 development of secondary cancelli above it. 



As stated above, Borg has indicated two families on the following 

 basis : 



Lichenoporidae, alveoli soon "roofed in" by a porous calcified layer, 

 with secondary alveoli above them ; the one central brood-chamber, 

 which may have lobes extending between the rays; zoarial budding 

 vertical. 



