GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 



Dimensions of branches of Acropora saludensis. 



481 



Branch No. 



Length. 



Diameter of 

 lower end. 



Diameter of 

 upper end. 



1 



mm. 

 28 

 34 



mm. 

 10 by 11 

 10.5 by 12 



mm. 

 9 by 11 



2 



8by 11.5 





The diameters are given for the stem proper, exclusive of the 

 corallite protuberances. The relatively greater width of the upper 

 end of No. 2 is due to its apparently being at the base of a bifurca- 

 tion. The form of the corallum was probably arborescent. 



The characters of the axial corallites not distinguishable in the 

 cotypes. The radial corallites, although not all of equal size, are 

 nearly all protuberant, a few subimmersed but no immersed coral- 

 lites were seen; however, immersed corallites might be present on 

 the basal part of the corallum. The form is ascending appressed 

 tubular; length measured along lower side, 2.5 to 3.5 mm.; lesser 

 diameter 1.5 to 2.5 mm.; greater diameter 1.75 to 2.5 mm.; lateral 

 compression relatively slight but apparent. Lower and side walls 

 well developed, thick, rather dense, outer surface usually strongly 

 costulate; upper edge of lower wall more or less rounded, somewhat 

 uncinate in some corallites. Upper wall only slightly protuberant 

 or obsolete. Apertures nariform or dimidiate. Primary septa 

 well developed; secondaries recognizable in many calices, appear to 

 be usually present. 



Coenenchyma relatively dense, surface closely beset with coarse, 

 somewhat elongate, more or less vermiculate granules, no well- 

 defined costules. 



Localities and geologic occurrence. — Canal Zone, Emperador lime- 

 stone, at station 60246, crossing of Panama Railroad over Rio Agua 

 Salud between Bohio Ridge and New Frijoles (cotypes); and at 

 station 6016, quarry, Empire, collected by T. W. Vaughan and 

 D. F. MacDonald. 



Antigua, station 6854, Rifle Butts, in the Antigua formation, 

 collected by T. W. Vaughan. 



Cotypes.— No. 325043, U.S.N.M. (2 specimens.) 



This species belong in the same group of Acropora as A. squarrosa 

 (Ehrenberg), A. rosaria (Dana), and A. murray en-sis Vaughan, 1 and is 

 referrable to the subgenus Rhahdocyathus of Brook. 



ACROPORA MURICATA (Linnaeus). 



1758. Milhpora murieata Linnaeus (part), Syst., Nat., ed. 10, p. 792. 

 1767. Madrepora murieata Linnaeus (part), Syst., Nat., ed. 12, p. 1279. 



1 Vaughan, T. W., Some shoal-water corals from Murray Island (Australia), Cocos-Keeling, and Fanning 

 Islands, Carnegie Institution, Washington Pub. 213, pp. 183-184, 1918. 



