390 BULLETIN 103, UliTITED STATES NATIONAL MUSEUM. 



can h& discriminated, it seems logical to recognize them as a species. 

 Sti/langia panamensis has a general resemblance to those specimens 

 of 0. canalis in which the corallites are small and the costae not 

 very prominent; but the corallites of 0. canalis are larger, and they 

 have not the lamellate columella of S. panamensis. Small-calicled 

 specimens with prominent, strongly alternating costae resemble 0. 

 imperatoris, and differ from the latter by their somewhat larger 

 calices and more numerous septa. The calices of 0. costata are 

 larger, the primary and secondary septa are subequal, and the col- 

 umella is more developed. In both 0. intermedia and 0. costata 

 the secondary septa are more developed. Larger suites of speci- 

 mens than are at present available may lead to the reduction of some 

 of these names to subspecific or varietal rank. 



11. ORBICELLA TAMPAENSIS, new species. 



Plate 95, figs. 1, 2, 2a, 3, 3a. 



1915. Orbicella cavernosa var. tampaensis Vaughan, novien nudum. XJ. S. Nat. 

 Mus. Bull. 90, p. 18. 



The corallum forms head-shaped masses up to the size of a mean's 

 fist. 



Calices deep, decidedly elevated, up to 4 or 4.5 mm.; diameter 

 from 6 to 10 mm. Costae prominent, distant: there are no or only 

 rudimentary costae corresponding to the last cycle of septa. 



Septa, distant, in four cycles, the fourth usually more or less in- 

 complete. The primaries and some or all of the secondaries, occa- 

 sionally a tertiary, reach the columella. Usually there are three or 

 four different sizes. On the inner ends of the primaries are paliform 

 teeth, below which the margins fall steeply to the bottom of the fossa. 

 Margins of the primaries exert as much as 1.5 mm.: those of secon- 

 daries almost as prominent: those of the tertiaries less prominent: 

 those of the quaternaries inconspicuous. Septa thickened in the wall. 



Columella much looser than in the other related species. 



Locality and geologic occurrence. — The "silex" bed of the Tampa 

 formation, Tampa, Florida. 



Type.—^o. 324900, U.S.N.M. (pi. 95. figs. 2, 2a.) 



Paratype.—^o. 324901, U.S.N.M. (pi. 95, fig. 1.) 



Paratype. — Wagner Free Institute of Science, Philadelphia (pi. 

 95, fig. 3). 



lla. ORBICELLA TAMPAENSIS var. SILECEN8IS, new variety. 



Plate 96. 



1915. OrbiceUa cavernosa var. silecensis Vaughan, nornen nudum, U. S. Nat. Ma?. 

 Bull. 90, p. 18. 



Corallum oblong, irregularly convex above; type about 16 cm. long, 

 11 cm. wide, and 9.5 cm. high. 



