496 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



This species resembles compressed specimens of Goniopora clevei 

 Vaughan, from which it is distinguishable by its thin septa, with 

 delicately dentate margins, 



GONIOPORA CLEVEI, new species. 



Plate 145, figs. 1, 2, 2a, 3, 4, 5, 5a, 6, 6a. 



Corallum branching. The type (pi. 145, figs. 2, 2a) is an irregu- 

 larly shaped portion of a branch, selected because it permits the 

 septal arrangement to be definitely determined. It is 44 mm. long; 

 greater diameter of lower end, 12 mm.; of bulged portion, 15.5 mm. 

 Probably some of the irregularity of form may be caused by erosion. 

 Another broken specimen, a paratype, is represented by plate 145^ 

 figure 1. 



Calices shallow, circular, or subcircular, 2 to 2.4 mm. in diameter. 

 They may be close together or separated by reticulate and costate 

 coenenchyma, as much as 1 mm. across; usually in the type, which is 

 worn, they appear distinctly separated from the bounding coenen- 

 chyma and sharply defined by a peripheral zone of synapticulae. 



There are 12 large lamellate septa with typical poritid arrangement, 

 solitary directive, four lateral pairs, and a directive triplet; the inner 

 ends of the laterals in the triplet are directed tov/ard, but not actually 

 fused, to the inner end of the principal directive. The outer ends of 

 these larger are often bifurcated, or costae (these are to be considered 

 rudimentary septa) exist between them, in some instances bringing 

 the number up to 24. Pali well developed, six in number. 



Columella tangle rather dense, with an axial tubercle. 



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

 P. T. Cleve, collector (type) ; stations 6893, 6894, 6966, Crocus Bay, 

 and 6970, 130 to 140 feet above sea level, east end of Road Bay, 

 Anguilla, collected by T. W. Vaughan. 



Canal Zone, station 6016, in the Emperador limestone, collected by 

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



Antigua, station 6854, Rifle Butts, Antigua formation, collected by 

 T. W. Vaughan. 



Type. — University of Upsala. 



Paratype. — -University of Upsala. 



Paraty pes. —'^ OS. 325111 (3 specimens), 325115 (1 specimen), 

 U.S.N.M., 



It was decidedly difficult to decide whether tliis species should be 

 referred to Porites or Goniopora. Bernard says: "These fossils with 

 12 central rays might almost be considered as transition forms toward 

 Porites having to all appearance only 12 septa; but whenever it can 

 be distinctly seen that a certain number of these septa fork before 

 they reach the wall, I assume that the forking is the vestige of the 

 fusion of the septa characteristic of Goniopora, and that therefore 

 there are more than 12." ^ 



1 Brit. Mus., Cat. Madrep. Corals, vol. 4, Gen. Goniopora, p. 21. 



