ADDITIONAL NOTES ON THE DEVELOPMENT OF THE 

 ARGULID.E, WITH DESCRIPTION OF A NEW SPECIES. 



H}^ Charles Branch Wilson, 



Department of Biologi/, Slate Xormal School, WestfieUl, Massachusetts. 



INTRODUCTION. 



This fifth paper in the series based on the Collection belonging to 

 the U. S. National Museum gives for the first time an account of the 

 newly hatched larva? of two of our conunon Argulids, one, Argtdus 

 fanduli^ a salt-water form, and the other, Argalus macu/o.m.s, fovind 

 only in fresh water. 



It also gives a description and figures of the male of Ai'c/ahis eafo,^- 

 t(mu\ which is the oldest of our North American species. 



In each of the three instances the form here described is the onl}" 

 one needed to complete a full account of the species, including its life 

 history. We have now, therefore, six native species whose entire 

 development is known, two infesting marine fishes and the other four 

 those inhabiting fresh water. 



For the opportunity of obtaining the present material the author is 

 indebted again to the courtesy and assistance extended by the Bureau 

 of Fisheries. TheAarya oH Arg (this /"uvdH/i was obtained during the 

 summer of 1905 while the author was working as a temporary assist- 

 ant at the station of the Bureau of Fisheries at Beaufort, North 

 Carolina. The other two forms were obtained during the present 

 summer, 1906, while holding a similar position at Lake Maxinkuckee, 

 Indiana. Grateful acknowledgment is here made for these favors. 



I. THE MALE OF ARGULUS CATOSTOMI Dana and Herrick. 



This was the first American Argulid to be described. For this 

 reason and also because of the excellent figures given by Dana and 

 Herrick with their original description, it was at once accepted by 

 European scientists and has taken the same place in America that is 

 occupied by Aigulus foliaceux in the European fauna. But Dana and 

 Herrick did not secure any specimens of males, and consequenth' their 

 species diagnosis was based entirely upon females. This has been the 



Proceedings U. S. National Museum, Vol. XXXII -No. 1 531 . 



411 



