﻿488 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Localities and geologic occurrence. — Alabama, Salt Mountain, 6 miles 

 south of Jackson, in the "coral limestone" above the top of the 

 Vicksburg group, collected by T. W. Vaughan (the type). 



Georgia, station 3381 and 3383, on Flint Kiver, respectively 4 and 7 

 miles below Bainbridge, in the base of the Chattahoochee formation, 

 collected by T. W. Vaughan. 



Antigua, West Indies, station 6854, Antigua formation at Rifle 

 Butts, collected by T. W. Vaughan. 



This species is of a high order of importance in the correlation of 

 American Oligocene deposits. 



The septal arrangement in A. alabamiensis is similar to that 

 of Porites in the presence of a plane of symmetry and the tendency 

 of the septa to fuse by their inner ends in pairs. The septa them- 

 selves, however, are very different, being lamellate, almost imper- 

 forate, and sharply differentiated from the surrounding coenenchyma. 



Professor Felix in his Anthozoen der Gosauschichten in den 

 Ostalpen * has redescribed and figured A. liaueri Reuss and A. 

 martiniana d'Orbigny. He does not speak of the bilateral sjanmetry 

 of the calices but both of his figures indicate such a condition, as in 

 each there are two opposite elongate septa that connect with each 

 other through the columella. I take it, then, that the calices of 

 A. martiniana are bilaterally symmetrical with the septa grouped 

 not very definitely in two's, three's, four's, or five's on each side of 

 the median plane. 



It seems probable that Actinacis may be intermediate in character 

 between the families Acroporidae and Poritidae. These notes and 

 suggestions are made in the hope that some one with the requisite 

 material may make a more careful study of the Cretaceous species 

 of tlie genus to determine the relations of those two families. 



Family PORITIDAE Dana. 



Genus GONIOPORA Quoy and Gaimard. 



1833. Goniopora Quoy and Gaimard, Voyage de V Astrolabe, Zool., vol. 4, p. 218. 

 Type-species. — Goniopora p>endunculata Quoy and Gaimard. 



GONIOPORA HILLI, new species. 



Plate 142, figs. 1, la. 



Corallum composed of flattish plates, which ma}^ be more than 20 

 cm. wide and 4 cm. thick and appear to have' grown in a subhori- 

 zontal position. 



The calices are polygonal, from 3 to 4 mm. in diameter, from 1 

 to 1.5 mm. deep, separated by walls from 0.75 to 1.25 mm. thick. 

 The walls are crossed by rather low costae, and in places there is some 



1 Palaeontographiea, vol. 49, pp. 176-17S, figs. 2, 3, 1903. 



