414 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Locality and geologic occurrence. — Station 6587, in limestone and 

 iron bearing sandstone, Tonosi, Panama, collected by D. F. Mac- 

 donald. This deposit is of Oligocene age (for fuller discussion, see 

 pages 207, 555, 582). Station 6881, Antigua formation, Willoughby 

 Bay, Antigua, collected by T. W. Vaughan. 



Type.—C&t. No. 324993, Ll.S.N.M. 



The only American fossil species at all nearly related to Favia 

 macdonaldi is one from the Oligocene or Miocene of Santo Domingo, 

 not yet described in print. It has smaller coraUites and relatively 

 more numerous septa than F. macdonaldi. These two species are Indo- 

 Pacific in their aflfinities, there being no nearly related species in 

 the Atlantic Ocean, with the possible exception of F. leptopliylla 

 Verrill, of which I have no specimen for comparison. It gives me 

 pleasure to attach the name of Doctor Macdonald to this really 

 handsome species of coral, which was discovered by him. 



Genus FAVITES Link. 



1807. Favites Link, Beschreib. Nat. SammL Rostock, pt. 3, p. 162. 



1901. Favites Vaughan, Geolog. Reichs Mus. Leiden SammL, ser. 2, voL 2, p. 21. 



1902. Favites Verrill, Conn. Acad. Arts and Sci. Trans., voL 11, p. 92. 

 1917. Favites Vaughan, Carnegie Inst. Washington Pub. 213, p. 109. 



Type-species. — Madrepora abdita Ellis and Solander. 



FAVITES MEXICANA, new species. 



Plate 103, figs. 2, 2a. 



Corallum massive, with more or less rounded or flattish upper 

 surface. Type a small broken specimen, 54 by 61 mm. in horizontal 

 diameter and 27 mm. thick. 



CoraUites polygonal, separated by narrow intercoralUte walls which 

 are barely 0.5 mm. thick. Diameter of coraUites as follows:. 



Diameter, in millimeters, of coraUites of Favites mexicana. 



Corallite 



1 

 9 

 7.5 



2 

 11 

 7.5 



3 



8.5 

 8 



4 



8.5 



7.5 



5 . 



9 

 7.5 



6 



7.5 

 6.6 



7 

 11.5 

 9 



8 



Greater diameter 



9 



Lesser diameter 



8.5 







Calices damaged so that their depth can not be definitely ascer- 

 tained, but apparently they were shallow. 



There are 46 septa in a corallite 7.5 by 6.5 mm. in diameter; of 

 these, 14 reach the columella and 23 are. small or rudimentary. 

 Usually three sizes of septa are recognizable; the tertiaries fuse to 

 the side of the secondaries, as a rule. Even the large septa are 

 relatively thin, not so tliick as the width of the interseptal loculi. 

 The inner ends of the principal septa are somewhat thickened and 

 p aliform lobes may have been present. 



