460 PROCEEDINGS OF THE NATIONAL MUSEUM ' vol.88 



The argulids in the United States National Museum have been 

 examined, as well as some from other sources. In cases where 

 synonymy was suspected, specimens of both species were examined 

 before any decision was made. Dr. Waldo L. Sclnnitt and Clarence 

 R. Shoemaker, of the staff at the Museum, were more than kind in 

 their efforts to facilitate the completion of the work. The latter was 

 especially helpful in the final preparation of the manuscript. The 

 American Museum of Natural History lent me the type specimen of 

 Argulus ingens for study. Dr. C. B. Wilson gave considerable assist- 

 ance in many ways, including the loan of specimens of A. japonicus. 

 Examples of this same species were sent to me from Japan by Dr. T. 

 Tokioka, of the Mitsui Institute of Marine Biology, and by Dr. 

 Watanabe, College of Fisheries, Hakodate, Japan. Dr. A. S. Pearse 

 lent me a number of specimens. The Bass Biological Station at 

 Englewood, Fla., lent me specimens of A. varians for comparative 

 purposes, and specimens were received from one or two other sources. 



One new species, Argulus floridensis^ is here described. The types 

 have been deposited in the collections of the National Museum. 



MORPHOLOGY 



For the purpose of description, it is necessary to designate the 

 appendages by name, but there is some confusion in the literature in 

 regard to the proper nomenclature. It is felt therefore that some 

 premise should be made for the application of the names used here. 



Considerable controversy surrounds the occurrence of a pair of 

 appendages in the proboscis. Claus (1875) expressed the view that 

 the other pair of "appendages" in the proboscis were maxillae. Wil- 

 son supports him in this. Grobben (1908) made dissections and cross 

 sections of the proboscis and showed that the so-called appendages 

 were really outgrowths of the lower lip and could not be true append- 

 ages. Martin (1932) studied the development of the embryo and 

 found no maxillae in the proboscis, but there was a pair of outgrowths 

 on the lower lip with hollow spines on them, which she called labial 

 spines. 



In some instances it seems that the true mandibles have been con- 

 fused with maxillae. Shortly before ecdysis the exoskeleton 

 loosens, leaving the mandible on the inside. In such a case one struc- 

 ture is the exact duplicate of the other. This is common on mature 

 specimens. An examination of cleared and other specimens from a 

 number of species has shown that Grobben and Martin are probably 

 correct, since no maxillae could be found. Labial spines are almost 

 always seen, sometimes projecting from the opening of the buccal 

 cavity. 



