﻿GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 505 



three rows in the wall, and a ring of thick ones, coinciding with the 

 palar ring, around the axis of each corallite. Trabeculae of columellar 

 tangle coarse; axial tubercle present. In longitudinal section there 

 are in 3.5 mm. about 11 synapticulae ; in the same distance about 10 

 vertical rods. The spaces of approximately the same thickness as 

 the solid parts, except that the median portion of a synapticula is 

 thinner than its ends. 



Locality and geologic occurrence. — Island of AnguiUa, West Indies, 

 collected by P. T. Cleve; Crocus Bay, AnguUla, collected by T. W. 

 Vaughan. 



Canal Zone, station 6016, in the Emperador limestone, Empire, 

 collected by T. W. Vaughan and D. F. MacDonald. 



Type. — ^University of Upsala. 



Duplicate specimen from the Cleve collection and other specimens 

 in the United States National Museum. 



This is an abundant species at Crocus Bay, AnguiUa, where I col- 

 lected it in both the lower and the upper part of the exposure on the 

 south side of the bay. The epitheca is not always distinct on the 

 lower surface, but I can not be sure whether it has been worn off or 

 was not developed. 



One of the two specimens from Empire, Canal Zone, is represented 

 by plate 150, figure 5. The caUcular characters are obscure but they 

 seem to be the same as those of P. anguiUensis. The general facies of 

 the specimens is identical Avith that of P. anguiUensis. 



Subgenus Synaraea Verrill. 

 1864. Synaraea Verrill, Mub. Comp. Zool. Bull., vol. 1, p. 42. 



Type-species. — ^None was designated by Verrill; therefore I select as 

 the type-species Porites erosa Dana, the first species in Ven-iU's list 

 of those referred by him to Synaraea. 



PORITES (SYNARAEA) HOWEI, new species. 



Plate 151, figs. 2, 2a, 3, 3a, 4. 



Corallum composed of rather small, sUghtly or greatly compressed, 

 even subpalmate, branches, on some of which longitudinal carinae are 

 well developed. Plate 151, figures 2, 3, 3a, are natural size illustra- 

 tions of two specimens. The thickness of the lower end of the speci- 

 men represented by figure 2 is 6 mm., of the upper end of the same 

 specimen about 5.5 mm.; the width and length of the specimen are 

 indicated by the figure. 



The calices are small, about 1 mm. in diameter, and occur more or 

 less in series from 5 to 18 mm. long between reticular coenenchymal 

 ridges, that range in thickness from a merely dividing partition up to 

 2 mm. wide, and in height up to a maximum of about 1 mm. 



Septa small, 12 in number, with the usual poritid arrangement. 

 The laterals of the triplet converge toward the inner end of the direc- 



