ACTHOR 8 ABSTRACT OF THIS PAPER ISSUED 

 BT THE BIBLIOGRAPHIC SERVICE, FEBRUARY 2 



THE DEVELOPMENT OF GELASIMUS AFTER 

 HATCHING 



O. W. HYMAN 



University of Tennessee College of Medicine 



TWELVE PLATES (eIGHTY-EIGHT FIGURES) 



During the summers of 1915 and 1916 at the U. S. Fisheries 

 Biological Station at Beaufort, North Carolina, while engaged in 

 an endeavor to rear crustacean larvae under artificial conditions, 

 I had an opportunity to study the habits and developmental 

 stages of Celasimus. While this study was only incidental to 

 the experiments in hand, I found the material so abundant and 

 other conditions so favorable that I have been enabled to review 

 the development in considerable detail: During the progress of 

 the study I have been aided greatly by the criticism and guidance 

 of Dr. H. V. Wilson and Mr. W. P. Hay. The work done at 

 Beaufort has been made a pleasure by the generous cooperation 

 unfailingly extended by Mr. S. F. Hildebrand, director of the 

 laboratory. 



OCCURRENCE OF THE ADULTS 



Of the many decapods at Beaufort, the three species of Celasi- 

 mus are perhaps the most numerous. Celasimus pugilator, the 

 common gray sand-fiddler or fiddler crab, is present almost every- 

 where, but is most abundant on the islands and shores where a 

 sandy beach is exposed at low tide. Conditions are especially 

 favorable if the beaches have a fringe of sedges which are in the 

 water at high tide. The crabs find a ready refuge in these when 

 frightened. 



C'elasimus pugnax is not so abundant as C. pugilator, but is 

 rather common. It is most often found in marshes, especially 

 where there is a considerable estuary formed at high tide, but where 

 the soft boggy marsh is exposed when the tide is out. One such 



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JOURXAL OF MORPHOLOGY, VOL. 33, NO. 2 



