ACTINIANS FROM THE BAHAMA ISLANDS 111 



can be associated with Lesueur's type species, and it is interesting 



accordingly to have an account of the structure of one of Lesueur's , 



species, in order that the true position of his genus may be determined. j 



Among the slides which Dr. Northrop had prepared I find a j 



number of a Zoanthid which he had provisionally designated No. 3, ^ 



and also a number of drawings of the same form, one of which was the ] 



figure of the group of individuals taken from preserved specimens I 



(fig. 4). Unfortunately, in the material forwarded me there were no ^ 



examples of this No. 3, but there were specimens of a form which the j 



accompanying label stated to have been collected by Dr. E. A. An- ! 



drews at Green Turtle Cay, Bahama Islands. This form resembled in j 



general appearance the drawing of No. 3, and preparations which I j 



made of it demonstrated with certainty its identity with Dr. Northrop's 1 



No. 3. j 



As regards its identity with Lesueur's M. nymphcea, there must • 



necessarily be a certain amount of uncertainty. It agrees with the '{ 



figure of M. auricula given in Lesueur's paper, and it answers the j 



generic description ; unfortunately, I find no memoranda of its colora- ! 



tion, and base the identification with nymphcEa, rather than with auri- 1 



cula, on the number of tentacles, which is about fifty, and which j 



Lesueur states to be about fifty in the former species and from twenty- \ 



six to thirty in the latter. 1 



The individual polyps composing a colony are seated close together j 



upon a coenenchymatous expansion, and reach in preserved specimens | 



a height of about 2-3.5 the measurement being taken from the j 



point of attachment to the coenenchyme. The diameter of the column 1 

 is about 3 or 4 mm. at the top, slightly less lower down, and the capitu- 



lum shows clearly a number of radiating ridges. | 



The column wall is smooth and without embedded particles of j 



foreign matter. In structure it resembles closely what has been | 



described for Zoanthus sociatus, the same large lacunar spaces occurring j 

 in the mesogloea, while the ectoderm is enclosed within the outermost 

 portion of the mesogloea, being covered by a mesogloeal subcuticula, 

 and by a cuticle, much more distinct in some specimens than in others. 



The sphincter muscle, which, for diagnostic purposes seems to be of ; 



great importance in the Zoantheae, is double, the two parts being well ] 



marked off from one another. The arrangement is shown in fig. 5, I 



and from this it will be seen that the upper portion of the sphincter is 1 



