82 PROCEEDINGS OF THE NATIONAL MUSEUM vol.83 



FAVIOSERIS, new genus 



Generic diagnosis. — Coralliim massive, tuberous, pedunculated. 

 Corallites slightly protuberant, cylindrical, or deformed by fission, 

 united by septocostae. No true corallite wall, but a ring of well- 

 developed synapticulae forms a perforate boundary. Septa thin, 

 imperforate, laminar, beaded on the upper edges, thickened pe- 

 ripherally near the thecal ring, continuous with the septocostae, 

 which are trabeculate and perforate, the perforations tending to 

 become filled up. The upper edges of the costae are rounded and 

 beaded. Columella absent, the axial space being quite empty. Dis- 

 sepiments not well developed. Reproduction by fission. 



Genotype. — Favioseris ariomalos^ new species, from the Upper 

 Cretaceous limestones of Jamaica, 



Remarks. — The family position of this genus is somewhat uncer- 

 tain because its general features are those of the Oulastreids, al- 

 though the septal structure is close to the Anabaciids in spite of the 

 laminar septa, which are more characteristic of the Agariciicls. The 

 Oulastreids, however, increase by gemmation, whereas fissiparity 

 is very marked in Favioseris. The laminar condition of the septa 

 seems to be due to subsequent filling of the original perforate trabec- 

 ular framework — a process that has not proceeded so far in the 

 septocostae as in the septa. No genus of the Anabaciidae seems 

 close to this form. Siderofungia Reis is perhaps related, but the 

 walls of that genus are very poorly developed and the calices have 

 the habit of Siderastrea. Crateroserls Tomes is supposed to have 

 imperforate septa and septocostae and therefore groups with the 

 x\gariciidae, but, as Gregory (1900, p. 189) has pointed out, this 

 apparent imperforate condition may be quite the opposite, in which 

 case Crateroseris would be near Dimorpharaea and PolyphyUastrea. 

 Crateroserls as it is now understood is near FavioseHs, except that 

 it increases by gemmation and has more protuberant corAllites. 

 For the present Favioseris is placed in the Agariciidae, 



FAVIOSERIS ANOMALOS, new species 

 Plate 4, Figures 19, 20 



Description. — Corallum massive, tuberous, arising from a narrow 

 base. The calices arc slightly protuberant, not bounded by a true 

 corallite wall, the margins being formed by the thickened outer ends 

 of the septa and a ring of synapticulae, as in the Oulastreids and 

 Siderastrea. They are originally circular in outline but are usually 

 oval or elliptical, owing to the fissiparous mode of increase. The 

 diameter of the circular calices averages 3 mm, that of the elongate 



