224 PROCEEDINGS OP THE PALEONTOLOGICAL SOCIETY 



Heim. Doctor Heim has recently completed a study of the geology of a por- 

 tion of Lower California. Certain of the species, which come from beds de- 

 scribed by him as Purissima nueva formation, are common to the Apalachicola 

 horizon at a number of localities around the Caribbean Sea. Some of these 

 species are Pecten condylomatus Dall, Pecten oxygonum optimum Brown and 

 Pilsbry, Rceta giMosa Gabb, Mactra dariensis Dall, Turritella tristis Brown. 



Pecten condylonatus is found in the Chattahoochee and Chipola beds of 

 Florida and, according to Dr. R. E. Dickerson, is present also in the Tuximn 

 beds of Mexico. Pecten oxygonum optimum is common in the Gatun beds at 

 I'anama. Racta gidhosa was described from the Peruvian Tertiary and is also 

 found, according to Doctor Dickerson, in the Miocene of the United States of 

 Colombia, the fauna of which is considered by him to be a phase of the Gatun 

 fauna. Mactra dariensis is found in the Gatun beds. Turritella tristis was 

 described from the Miocene of Costa Rica. 



The recognition of this fauna in Lower California is important in that it ap- 

 parently indicates a direct connection between the Pacific and Atlantic oceans 

 somewhere in the region of Central America during the Apalachicola period of 

 deposition. 



TERTIARY MOLLUSKS AND ECHINODER3I8 FROM THE VICINITY OF TUXPAN, 



MEXICO 



BY K. E. DICKERSON AND W. S. W. KEW 



{Abstract) 



An interesting fauna has been collected recently by Prof. E. T. Dumble and 

 Prof. W. F. Cummins from the Tertiary of the Gulf coast of Mexico. In this 

 collection are several echinoderms which were described by Cotteau from for- 

 mations of the islands of Cuba, Angiillla, and Saint Bartholomew. These were 

 assigned to the Eocene l)y P. T. Cleve. 



The echinoderm fauna was collected from seventeen localities north and 

 south of Tuxpan. Of the fourteen forms found, Clgpeaster cuhensis Cotteau, 

 of the Cuban Miocene, is most common. It is associated with Agassizia clevei 

 Cotteau, from Saint Bartholomew, and Macropneustes antillarum Cotteau. 

 from questionable Eocene of Saint Bartholomew and Cuba. Associated with 

 the Antillean species are ScJiizaster scherzcri Gabb and Horn, from the Costa 

 liican Miocene; Lovenia, new species; Glypeaster, cf. rogcrsi (Morton) ; Scu- 

 tclla, new species; Mctalui, new species. These forms are associated with 

 J'ecten condylomatus Dall, of the Chipola horizon of Florida; Pecten oxygonum 

 optimum Brown and Pilsbr.\', J'ecten gatunensis Toula, Pecten levicostatus 

 Toula, dementia dariana Conrad, Turritella altalira Conrad, Malea ringens 

 Swainson, of the (iatnn beds ; Fleas mississippiensis Conrad, of the Vicksburg 

 and Bowden horizons ; Conus interstinctus Guppy, of the Bowden beds ; Hemi- 

 pristis scrra Agassiz, of the Maryland and the California Miocene, and several 

 other species which are characteristic of the Gatun beds. The fauna, as a 

 whole, is littoral and is apparently an inshore facies of the Bowden and Chat- 

 tahoochee liorizons. 



The fauna submitted by Professor Dumble and Professor Cummins suggests 

 that certain so-called Eocene beds of Cuba, Anguilla, and Saint Bartholomew 



