FAUNA OF ORTHAULAX PUGNAX ZONE. 17 



occur in the lower Oligocene of the Panama Canal Zone, and at least 

 one of them has. been obtained in Santo Domingo, Antigua, and 

 Anguilla. 



Above the Orthaulax zone we find 51 of its species surviving in 

 the Cardium cestum zone, but only 14 reach the zone of Scapharca 

 dodona. 



Fifteen occur in extra-Floridian Miocene beds, but only 3 in the 

 Floridian Miocene; 11 are found in the Pliocene of south Florida, 

 5 in the Florida Pleistocene, while 23 survive in the recent fauna. 



SOURCES OF MATERIAL. 



Specimens were long distributed by tourists as curios. The first 

 material which was available for this monograph was that collected 

 by Professor Heilprin in 1888. In the following year the present 

 writer made a large collection, and subsequently the locality was vis- 

 ited by Capt. Frank Burns for the same purpose. Mr. Joseph Will- 

 cox, Mr. James Shepard and Miss Shepard, Mr. F. W. Crosby, and 

 Mr. W. O. Crosby kindly contributed valuable specimens. Mr. E. J. 

 Post, of Tampa, has made a practice of collecting at Ballast Point 

 for a long time. An excellent series was purchased from him, and 

 he most kindly allowed the study of the material he had on hand at 

 a later time to make the present paper more complete. Some speci- 

 mens were also contributed by Mr. L. G. Newman and Mr. La 

 Penotiere. 



ACKNOWLEDGMENTS. 



The present writer desires to express his obligations to many mem- 

 bers of the United States Geological Survey for unpublished material 

 and notes on the geology, especially to Dr. T. Wayland Vaughan 

 and Mr. George C. Matson, whose contributions have been of great 

 importance. 



The Director of the Survey has kindly permitted the use of the 

 drawings made by Survey artists. 



To Mr. Joseph Willcox and the Wagner Free Institute of Science, 

 Philadelphia, thanks are due for assistance on numerous occasions 

 and especially for permission to use here some of the figures drawn 

 by J. C. McConnell to illustrate the third volume of the Transactions 

 of the Institute. To the Academy of Natural Sciences we owe the 

 opportunity of consulting the types of species described by Professor 

 Heilprin and W. M. Gabb. 



To several kind correspondents in Florida, especially Mr. E. J. 

 Post, are due thanks for specimens lent for examination or con- 

 tributed to the National collection. 



This paper is published by permission of the Director of the 

 United States Geological Survey. 

 54907°— Bull. 90—15 2 



