GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 491 



very probable that two of these are only varieties of G. decaturensis, 

 they are named and described as such. 



GONIOPORA DECATURENSIS var. SILICENSIS, new variety. 



Plate 143, figs. 2, 2a. 



This is a specimen 113 mm. long, 54 mm. wide, and 20 mm. thick. 

 The upper surface is slightly undulated, there is one deep depression, 

 but it may have been caused by a burrowing animal or the surface 

 may have been corroded. 



Calices 2.5 to 4 mm. in diameter, larger than in typical G. decaturen- 

 sis. Septa decidedly thin; texture light and fragile. 



Locality and geologic occurrence. — Georgia, station 3381, Flint River, 

 Blue Springs, 4 miles below Bainbridge, in the base of the Chatta- 

 hoochee formation, collected by T. W. Vaughan. 



Type— No. 325026, U.S.N.M. 



GONIOPORA DECATURENSIS var. BAINBRIDGENSIS, new variety. 



Plate 143, figs. 3, 3a. 



Two small, inflated, rounded specimens are referred to this variety. 

 No. 1, length 26.5 mm., width 25 mm., thickness 13.5 mm.; 

 No. 2 (type), length 33 mm., width 24 mm., thickness 19 mm. 



Calices superficial, about 3 mm. in diameter. 



Septa moderately thick. 



These specimens are separated from typical G. decaturensis solely 

 on the growth form. 



Locality and geologic occurrence. — Georgia, station 3381, Flint River, 

 Blue Springs, 4 miles below Bainbridge, in the base of the Chatta- 

 hoochee formation, collected by T. W. Vaughan. 



Type.— No. 325029, U.S.N.M. 



GONIOPORA REGULARIS (Duncan). 



1863. Alveopora daedalaea var. regularis Duncan, Geol. Soc. London Quart. Journ., 



vol. 19, p. 42G, pi. 14, figs. 4a, 4c. 

 1867. Alveopora daedalaea Duncan, Geol. Soc. London Quart. Journ., vol. 24, p. 25. 

 1901. Alveopora regularis Vaughan, Geolog. Reichs. Mus. Leiden Samml., ser. 2, 



vol. 2, p. 71. 



Duncan's material of this coral is very poor, consisting of casts and 

 mineral replacements of the original skeleton; and, as I pointed out 

 in my paper cited in the synonomy, he incorrectly gave the dimensions 

 of the corallites. The diameter is not il \ line" [ = about 1 mm.] as 

 stated by Duncan, but is usually 2 mm., with a range from 1.5 to 2.5 

 mm. I have three photographs of Duncan's type (No. 12949, Coll. 

 Geol. Soc. London), and after having made a large collection in 

 Antigua identify with certainty the species represented by Duncan's 

 poor specimen. It is a species of Goniopora and is one of the common- 

 est corals in Antigue, where I obtained about 30 good specimens. 



