194 1 CATALOGUE OF FISHES OF TORTUGAS 



IX 



draft did not reach me. In such instances it was necessary to review the field 

 data, and either to draw up new accounts or to revise and extend old ones. It was 

 necessary, also, to consult his notebooks for the preparation of accounts of those 

 species that had not been treated at all in the manuscript. Inasmuch as the six 

 large ledgerlike notebooks, and several smaller ones, were not indexed, it was 

 necessary to prepare an index. It is evident, then, that considerable preliminary 

 work had to be done before the work of completing the manuscript could be 

 undertaken. 



The collection also was received wholly unorganized. Unfortunately few of 

 the specimens, probably less than 5 per cent, were labeled either as to locality or 

 as to their identity. Sometimes it was possible to supply these data from field 

 notes. More often it was necessary to identify the specimens anew and simply to 

 label them as from "Tortugas, Florida." 



It is understood that Dr. Longley knew the local fish fauna so well that he did 

 not need labels. However, with due respect to this honest and sincere worker, 

 the desirability of providing adequate labels, because of the uncertainty of human 

 life, is well illustrated here. Preachment of course is out of place, but I am sure 

 that taxonomists in general would join me in admonishing biologists and col- 

 lectors of scientific specimens in general to furnish adequate data. 



An effort was made throughout the work to identify the specimens, which are 

 deposited in the National Museum, in accordance with Dr. Longley 's classifica- 

 tion, as set forth in his manuscript, except in those few instances when he was 

 obviously in error. It was not always easy to follow his classification, as some- 

 times diagnostic characters were not given, or they were based too largely on 

 color in life to be usable for preserved specimens. Difficulty in making identifica- 

 tions was met because of faded colors, especially in the Pomacentridae and the 

 Scaridae. In some instances I have supplied diagnostic characters. In others, if it 

 seemed desirable because of new species or additional information discovered, 

 keys were introduced. 



The rather frequent references to and comparisons with fishes from Key West, 

 Florida, in sections added by me, result from my familiarity with the closely 

 allied fish fauna of that vicinity, after more than a year spent there in study. 



As Dr. Longley, in the part of this introduction prepared by him, did not 

 describe his method of work, which seems important, I may point out that he 

 was a pioneer in using the diving helmet. Most of the observations reported in 

 this book are based on what he actually saw while living, as it were, under water 

 with the fish. He stated in his notes that many fishes are unafraid of the diver, 

 and that it was possible to observe their behavior and details of color at close 

 range. He used a wax-covered slate for taking notes under water, which later 

 were transcribed on paper. 



The under-water photographs published herewith were taken with a camera 

 enclosed in a watertight brass box, with a front and a rear window of plate glass. 

 The box was built with external attachments for manipulating the mechanisms 

 of the camera. 



The sequence of the families and usually of the genera is in agreement with 



