GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 369 



ones are wide, nearly equal, all reaching the rather large columella; their edges are 

 perpendicular and finely, sharply serrate, with slender, rough teeth, which extend 

 also over their prominent, obtuse, or subtruncate summits, giving them a rough 

 appearance under a lens; their surfaces are also rough or hispid with numerous conical 

 grains. The septa of the third cycle are narrow, straight, and usually reach about 

 halfway to the columella. 



TLe costae are thick, not very high, meeting or inosculating between the calicles, 

 and covered with a single row of small slender, rough spinules. The columella is 

 well developed formed of contorted trabecular processes, and often having a small 

 pit in the center and a few erect spinules, similar to the slender, rough, paliform teeth 

 that often (but not regularly) stand at the base of some of the 12 larger septa. 



In sections the walls are very thick and nearly solid. The endothecal dissepi- 

 ments are small, thin, irregularly convex or flat above. The calicles are not filled 

 up below, or only slightly encroached upon, by a deposit between some of the septa. 

 Diameter of the calicles 3 to 3.5 mm.; distance between them mostly 2 to 4 mm., 

 often more. 



Florida Reefs (Maj. E. B. Hunt), Yale Museum, No. 98. Near Nassau, N. P. 

 (coll. R. P. Whitfield), Amer. Mus., New York. 



This has the general appearance of 0. annularis, but with calicles larger than usual 

 and decidedly farther apart. The walls and exotheca are much thicker and more 

 solid, and the endothecal cells are fewer and less regular. The sharply spinulose 

 and hispid septa and costae are also characteristic. The exothecal deposits are 

 nearly as solid as in Oculina. 



A Nassau specimen, in the American Museum, is an irregular, rounded mass, about 

 5 inches in diameter, and 3 to 4 thick, with a a lobulated surface. The coral is heavy 

 and solid; the surface of the coenenchyma is spinulose; the costae well developed. 

 The calicles are more variable in size than in the type, in some places being one-half 

 smaller and closely crowded. Coll. R. P. Whitfield. 



The form of 0. Mspidula Verrill, in which the upper surface is 

 lobulate, is common on the reef off Cocoanut Point, Andros Island, 

 Bahamas, where a suite of 12 specimens was obtained by the Anton 

 Bohrn expedition in 1914. The calices of most of these specimens 

 are precisely as in the type of Professor Verrill's 0. Mspidula (frag- 

 ment of type No. 40476, U.S.N.M.) and Gregory's Echinopora franski 

 (fragment of type No. 156455, U.S.N.M.), but in both growth 

 form and calicular characters there is intergradation with the more 

 usual characters of 0. annularis. Plate 76, figures 3, 3a illustrates 

 the appearance of one of the specimens with lobulate surface. 



A specimen from Port Castries, Santa Lucia (pi. 83, fig. 2), shows 

 a variation worthy of note. In all of the variations so far described, 

 the primary and secondary septa are constantly subequal, uniformly 

 reaching the columella. In the Santa Lucia specimen a secondary 

 septum in some systems is shorter and thinner than a primary; and 

 in some calices there are as many as 30 septa. This specimen is of 

 importance for comparison with PJiyllocoenia sculpta var. tegula 

 Duncan and EcMnopora franksi Gregory. 



These remarks cover the variation of the recent specimens that 

 I have actually been able to study. Pourtales, Verrill, and Duerden, 

 however, have added other observations. 



