184 Notes on Some Actinians from the Bahama Islands, 



cesses being rather low, the ectoderm possessing but few 

 neraatocysts, and the endoderm being thin with only a few 

 Zooxanthellae. The wall of the protrusion differs not a little from 

 this ; thus the mesogloea is much thinner, the muscle processes 

 are aborted, the ectoderm is richly provided with nematocysts, 

 so that the protrusions might be termed batteries of nematocysts,. 

 and the endoderm is thick and abundantly packed with Zooxan- 

 thella;. 



The tentacles leave exposed a considerable portion of the disc, 

 perhaps about half its breadth, and this portion is smooth and 

 slightly concave. Its mesogloea is rather thin and the muscle 

 processes are but moderate in length. No muscle cells are 

 enclosed within the mesogloea. The mouth is not elevated above 

 the disc and is almost circular in the preserved specimens, the 

 gonidial angles being but slightly marked. 



In tlie single specimen in which I counted the mesenteries there 

 were forty-eight pairs, a number which agrees with that found 

 by Dr. Northrop in another specimen. Of these forty-eight pairs 

 but six are perfect, forming the first cycle ; the six pairs of the 

 second cycle nearly equal the first cycle in size, but are imper- 

 fect; the twelve of the third cycle are considerably smaller, 

 though still quite muscular ; while the twenty-four pairs of the 

 fourth C3^cle, though extending some distance in from the body 

 wall, yet have their musculature but feebly developed. Two pairs 

 of directives are present and are attached to a greater extent of 

 the stomatodseum than are the other mesenteries of the first 

 cycle. The longitudinal muscles are well developed and have in 

 section the form represented in fig. 2. The parieto-basilar muscles 

 are but feebly represented and do not require special description. 

 Numerous acontia occur, a fact that was discovered by Dr. Nor- 

 throp. None of the specimens examined possessed reproductive 

 organs, so that nothing can be said regarding the distribution of 

 these organs. 



There seems to be no room for doubt but that this form is 

 identical with that described by Duchassaing and Michelotti in 

 their first paper ('60) as Gapnea lucida though later ('66) assigned 

 to the genus Heteractis, a genus established by Milne-Edwards for 

 the reception of the Actinia aurora of Quoy and Gaimard. 

 Andres ('83) has referred it to the genus Ragactis, which he 

 established for a species, R. pulchra^ discovered by him in the- 



