•336 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Calices small, apertures from 0.5 to 0.75 mm. in diameter; crowded, 

 maximum distance apart 1 mm., usually less 'than 0.5 mm. — that is, 

 Jess than a caUcular diameter apart. Margins very slightly or not 

 at all elevated; upper wall in places forms an obscure upper lip. 



Septa, the six primaries distinct, fuse in the calicular axis, directive 

 plane well marked; secondaries not recognizable in the type-speci- 

 mens and appear to be absent, but it is possible that they were present 

 und have been destroyed by fossilization. 



Columella a compressed style, not prominent. 



Coenenchyma, surface badly worn in the type, but some granula- 

 tions may be distinguished. 



Locality and geologic occurrence. — Canal Zone, station 6016, in the 

 Emperador limestone, quarry, Empire, collected by T. W. Vaughan 

 iind D. F. MacDonald. 



Type.—^o. 324763, U.S.N.M. 



S. panamensis has smaller and more crowded calices than S. 

 dmperatoris. 



STYLOPHORA AFFINIS Duncan. 



1863. Stylophora affinis Duncan, Geol. Soc. London Quart. Journ., vol. 19, p. 436, 

 pi. 16, fig. 4. 



1866. Reussia affinis Duchassaing and Michelotti, Sup. Corall. Antilles, p. 70 

 (of reprint). 



1867. Stylophora affinis Duncan, Geol. Soc. London Quart. Journ., vol. 24, p. 25. 

 1870. Reussia affinis Duchassaing, Rev. Zooph. Antilles, p. 26, 



Original description. — ''Corallum branched, large; branches nearly 

 ■cyhndrical, leaving the stem at an acute angle, slightly flattened on 

 one side. The largest stem is four-fifths inch in diameter. Blunt, 

 .^-borted, branchlike swellings exist on some of the larger stems. 

 CoralUtes radiating from the center of the stem and branches, sepa- 

 rated by about their own width of dense coenenchyma, which is seen, 

 in the larger specimens, to be very slightly cellular. Walls not distin- 

 guishable from the coenenchyma in the substance of the mass, but 

 slightly raised into a very shallow crateriform edge on the surface. 

 "Calices circular, a very Httle raised as crateriform elevations, very 

 -numerous, disposed irregularly, but very nearly equidistant in some 

 places and less so in others; margins sharp. Diameter one- thirtieth 

 inch [0.83 mm.], rarely larger. The cahcular margin, when well pre- 

 '^served, looks like a little ring placed on the intercalicular space, and 

 the small styHform columella renders the appearance very distinct. 

 Intercalicular spaces marked by a continuous and rigid line, which, 

 being in the part of the spaces at the base of the calicular eleva- 

 tions, and being continued round each calice, is, from its general 

 straightness, formed into irregular polygons. The fine is sensibly 

 jraised, convex, and now and then dentated. Between the fine and 

 the calicular margin there are distinct papillae, one row at the very 



