;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, 

 less than a calicular 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 

 and 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 

 and D. F. MacDonald. 



Type.— No. 324763, U.S.N.M. 



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

 imperatoris . 



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 

 cylindrical, leaving the stem at an acute angle, slightly flattened on 

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

 aborted, branchlike swellings exist on some of the larger stems. 

 Corallites 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 little 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 calicular margin, when well pre- 

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

 the small styliform 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 line is sensibly 

 raised, convex, and now and then dentated. Between the line and 

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



