GEOLOGY AND PALEONTOLOGY OP THE CANAL ZONE. 495 



The lower end of each specimen and the tops of Nos. 3 and 4 are 

 broken. Some coralla are evidently formed of rather thin, branching 

 plates. 



Calices polygonal, usual diameter 3 mm., young calices about 2 

 mm. in diameter, an occasional large one as much as 4 mm.; depth 

 from 1 to 1.25 mm.; separated by walls from 0.75 to 1.25 mm. thick. 

 The walls are crossed by costae and usually form a fairly regular 

 network around the calicular cavities, but in places there is con- 

 siderable intercalicular reticulum. In places there are low, rather 

 indefinite ridges which may extend the length of as many as four 

 calices. The tops of the walls are rounded or subacute. 



The septa are normal gonioporid in number and arrangement; 

 they are thick at the wall, becomes thinner toward the center; 

 their upper part narrow, gradually sloping to the columella tangle, 

 which is joined by the primaries and secondaries; margins with about 

 6 fine dentations. 



Columella tangle not very conspicuous. 



Locality and geologic horizon. — Canal Zone, station 6016, quarry in 

 the Emperador limestone, Empire, collected by T. W. Vaughan and 

 D. F.'MacDonald. 



Anguilla, station 6966, middle bed, Crocus Bay, collected by 

 T. W. Vaughan. 



Coty pes. — N os. 325052, U.S.N.M. (3 specimens). 



I am not certain the G. canalis is really different from G. impera- 

 toris. 



GONIOPORA PORTORICENSIS. new species. 



Plate 146, figs. 4, 5. 



Corallum ramous, branches rounded in cross section or very com- 

 pressed, a branch of the latter form is 34 mm. wide with a maximum 

 thickness of about 9 mm. 



Calices polygonal, shallow, usual diameter 2 mm. The outer ends 

 of the septa are flattened and fused together, separating the calicular 

 depressions by a wall about 0.5 mm. thick. 



Septa delicate, very perforate, in three complete cycles. Margins 

 finely and delicately denticulate; about five small thin teeth on a 

 long septum. Pali appear to be poorly developed, not specially 

 differentiated from the ordinary septal dentations. 



Columella weakly developed. 



Locality and geologic occurrence.— Porto Rico, station 3191, 4 

 miles west of Lares, Pepino formation, collected by R. T. Hill. 



Antigua, stations 6854, Rifle Butts; 6881, Willoughby Bay, in the 

 Antigua formation, collected by T. W. Vaughan. 



Type.— No. 325061, U.S.N.M. 



Paratype.—'No. 325060, U.S.N.M. 



