GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 497 



While in Anguilla in 1914 I collected about 40 identifiable speci- 

 mens of this species, and am illustrating a series on plate 145, figures 

 3, 4, 5, 5a. The branches are thickish and blunt-ended, having some 

 resemblance in growth form to the thicker-branched forms of Porites 

 porites, such as are common on the reefs on the east side of Andros 

 Island, Bahamas. The calices of these specimens are not perfectly 

 preserved, but in many a third cycle of septa is clearly recognizable. 

 I therefore am convinced that the species is referable to Goniopora. 



Doctor MacDonald and I collected in the quarries at Empire, Canal 

 Zone, a number of specimens that seem completely to agree with the 

 Anguillan specimens. One of these is represented by plate 145, 

 figures 6, 6a. 



Flattened specimens of G. clevei resemble specimen of G. portori- 

 censis, but the latter has thinner and more delicately dentate septa, 

 and in it the tertiary septa are more developed. 



GONIOPORA CASCADENSIS. new species. 



Plate 146, figs. 6, 6a, 66, 7, 8, 9. 



Corallum composed of relatively slender, subterete branches. A 

 branch segment 40 mm. long is 9 by 10 mm. in diameter at the lower 

 end and 8 by 9 mm. in diameter at the upper end, showing 1 mm. 

 decrease in diameter for 40 mm. in length; but branches may be 

 thicker, up to as much as 15 mm. in diameter. 



Calices slightly excavated, polygonal, from 1.75 to 2.5 mm. in 

 diameter, separated by more or less discontinuous walls, in some 

 places a straight or zigzag wall ridge is traceable, but in other places 

 there seems to be none. Where there is a wall ridge, rather coarse 

 mural denticles corresponding to the outer ends of the septa are 

 present. In places mural reticulum is present and coarse radial skele- 

 tal structures are clearly traceable through it. 



There are 12 large septa which extend to the columellar tangle, 

 and about 12 small septa which fuse in pairs to the sides of an included 

 septum (assumed to a secondary) about halfway between the wall 

 and the columellar tangle. The septal granules seem to be arranged 

 according to the following scheme: A ring of outer granules which 

 are adherent to or only slightly detached from the wall, a ring of 

 intermediate granules which correspond in position to the place of 

 fusion of the small (tertiary) septa to the sides of the secondaries, 

 and an inner ring of granules which form p aliform knots around the 

 periphery of the columella tangle. The intermediate and inner rings 

 seem constantly recognizable, but the outer ring 'is not always defi- 

 nitely developed. The interseptal loculi are about as wide as the 

 thickness of the septa. 



Columella tangle well developed; width more than one-third the 

 diameter of the calice. In some calice a central styliform process is 

 distinguishable. 



