AMOS PEASLEE BROWN. xi 



importance that he was led to make still another trip in August for 

 the purpose of securing additional material. 



Brown brought his collections to the Academy of Natural Sci- 

 ences, and with the assistance of Dr. Henry A. Pilsbry, the noted 

 malacologist, began to work them up for publication. For the next 

 three years a large part of his spare time was spent in Dr. Pilsbry's 

 quarters at the museum. The latter, being actively engaged in pub- 

 lication, stimulated Brown to prepare many papers which would 

 probably never have appeared had he been left entirely to himself, 

 since he was always skeptical as to the importance of his researches 

 and the advisability of publishing the results. In several instances 

 Dr. Pilsbry gave him the benefit of his vast knowledge of the mol- 

 lusca, in working up the systematic portion of the reports, and they 

 were published under their joint authorship. 



Thanks to Dr. Pilsbry's advice and stimulation Brown published 

 more papers during this period than in all the rest of his career. As 

 joint authors they prepared in 191 1 a paper on "The Fauna of the 

 Gatun Formation, Isthmus of Panama, "^^ based upon Brown's col- 

 lections of the previous year. In the introduction he explains that 

 the study of the specimens fully bore out his impression, formed 

 during a hasty reconnaissance of the exposures along the Canal and 

 railway, that the several shell-bearing formations which have been 

 given distinctive names really all belong to one stratigraphic unit. 

 He and Dr. Pilsbry moreover agree that this is more likely to prove 

 to be Oligocene than Eocene, as Dall has regarded it, and call at- 

 tention to its resemblance to the Santo Domingo beds studied by 

 Gabb. Thirty-seven new species were described in this paper, while 

 thirty-three more were named in two supplementary publications,^^ 

 based upon material obtained by Professor W. B. Scott, in 191 1. 

 Brown was also associated with Dr. Pilsbry in a report on a collec- 

 tion of fossils from Wilmington, N. C.,-° which was received at the 

 Academy about this time, while he published independently an ac- 



^'^ " Fauna of the Gatun Formation, Isthmus of Panama," Proc. Acad. 

 Nat. Sci. Phila., 191 1, pp. 336-373. 



19 " Fauna of the Gatun Formation, Isthmus of Panama." XL. Proc. Acad. 

 Nat. Sci. Phila., 1912, pp. 500-519. "Two Collections of Pleistocene Fossils 

 from the Isthmus of Panama," ibid.. 1913, pp. 493-500. 



20 " Notes on a Collection of Fossils from Wilmington," ibid., 1912, pp. 

 152-153- 



