412 BULLETIlsr 103, UNITED STATES NATIONAL MUSEUM. 



Calices irregular in form, subpolygonal or more or less elliptical in 

 outline; sliglitly excavated. Diameter from 3 to 4.5 mm.; depth 

 about 1 mm. Intervening walls narrow, acute. 



Septa in two complete cycles. The primaries are rather thick and 

 reach the calicular center; in fully developed calices all or nearly all 

 of the secondaries also extend to the center, tertiary septa absent or 

 very rudimentary. Margins not exsert; within the calices straight 

 or slightly concave upward. There are no recognizable dentations, 

 but on the septal edges and faces there are many rather large granu- 

 lations. Interseptal ^oculi wide and open. 



Columella false, formed by the fusion of the thickened inner ends 

 of the principal septa. There are no trabecular septal processes. 



Asexual reproduction by intercorallite budding. 



Locality and geologic occurrence.- — Republic of Colombia, station 

 7873, Gatun formation, about 0.5 km. west of Usiacuri, collected by 

 G. C. Matson. 



Type.— No. 324956, U.S.N.M. 



Septastrea matsoni closely resembles young coralla of S. mary- 

 landica (Conrad) Vaughan, from the St. Marys and Yorktown forma- 

 tions in Virginia.^ It is interesting to find in Colombia a species of 

 Septastrea that is doubtfully distinguishable from a species in the 

 Miocene of Virginia. The fossiliferous marl that almost surromids 

 Usiacuri appears to be the same formation as the Gatun formation, or 

 to be a part of the Gatun formation. Although the evidence sup- 

 plied by this coral is not great, it is at least indicative of the late 

 Miocene age of a part if not all of the Gatun formation. 



Family FAVIIDAE Gregory. 



Genus FAVIA Oken. 



1815. Favia Oken, Lehrb. Naturgesch., Th. 3, Abth. 1, p. 67. 



1857. Favia Milne Edwards and Haime, Hist. nat. Corall, vol. 2, p. 426. 



1902. Favia Verrill, Conn. Acad. Arts and Sci. Trans., vol. 11, p. 88. 



1917. Favia Vaughan, Carnegie Inst. Washington Pub. 213, p. 100. 



Type-species. — Madrepora fragum Esper . 



FAVIA FRAGUM (Esper). 



1795. Madrepora fragum Esper, Pflanzenth., Fortsetz., p. 79., pi. 64, figs. 1, 2. 

 1901. Favia fragum Vaughan, Geol. Reichs Mus. Leiden Samml., ser. 2, vol. 2, p. 

 34 (with synonomy ) . 



1901. Favia fragum Vaughan, U. S. Fish Com. Bull, for 1900, vol. 2, p. 303, pi. 3. 



1902. Favia fragum Verrill, Conn. Acad. Arts and Sci. Trans., vol. 11, p. 90, 



pi. 13, figs. 1, 2. 



1915. Favia fragum Vaughan, Washington Acad. Sci. Journ., vol. 5, p. 596. 



1916. Favta fragum Vaughan, Carnegie Inst. Washington Yearbook No. 14, pp. 



224, 227. 



1 See Vaughan, T. W., Anthozoa, Maryland Geol. Survey, Miocene, pp. 444-447, pi. 126, figs, la, 16, 2; 

 pi. 127, figs. 1-3; pi. 128, figs. 1, 2; pi. 129, 1904. 



