SYNOPSIS OF NORTH AMERICAN INVERTE- 

 BRATES. 



XIV. Part IV. The Scyphomedus^:. 



CHAS. W. HARGITT. 



The following synopsis is a continuation of that upon Hydro- 

 medusae which appeared as XIV of the American Xaturalist 

 series, during April, May and July, 1901. 



As in the preceding parts, while depending- largely upon my 

 own records of the Scyphomedusae, I have at the same time 

 drawn freely upon the literature wherever found, but chiefly 

 Haeckel's « System der Medusen " and to a less extent Mayer's 

 numerous papers. (/»////. Mas. Comp. Zoo/.) Kewkes papers, 

 chiefly of the same series, including also L. Agassiz, " Contr. 

 A T at. Hist. United States," 1862, and A. Agassiz' "Catalog 



In only a few cases has any attempt been made to present 

 accounts of the synonymy of the several species, and then only 



In general form, habit, structure and distribution the Scypho- 

 medus;e have much in common with the Hydromedusas and 

 probably sustain a more intimate relation to them than to any 

 other ccelenterate Class. 



They may however be somewhat sharply distinguished by the 

 following characters : 



1. Absence of a true velum. The velarium of the Cubo- 

 medusae has important structural differences, though doubtless 



2. Sense organs when present are modified tentacles, 

 variously designated as tentaculocysts, rhopalia, etc. 



3. Entodermic origin of sexual products. 



In development there is general correspondence between this 

 and the preceding Class. In some the medusa arises by direct 



