ZOOLOGY OF THE BERMUDAS. 127 



the margin to the upper row of tubercles, is a single s(rong 

 sphincter muscle imbedded in the mesogloea, and occupying 

 nearlj' its whole thickness. 



All the specimens were in a state of strong contraction, and 

 I was not able to see the tentacles. Duchassaing and Michelotti 

 state that they are small tubercles. M3' sections show that 

 they are arranged in two cycles. It is also evident that they 

 are short, but they can scarcely be termed tubercles. Their 

 mesogloea is thick, especially toward the base, thinning out 

 somewhat tow'ards the apex. Its outer surface is thrown into 

 ratlier strong muscular processes. 



The surface of the stomatodamm is thrown into numerous 

 rather high folds, the ectoderm being elevated on slender proc- 

 esses of the mesogloea. 



The mesenteries are arranged on the microtypus and num- 

 ber twonty-two pairs. Towards their base the mesogloea is 

 very thick, diminishing gradually towards the distal edge. 

 Just at the base there is a sudden diminution of the thiekues-s, 

 so that they are attached to the column wall by a thin pedicle. 

 Tlie basal portion contains the usual canal, and in addition 

 there are numerous lacunar, similar to those of the column wall 

 in every respect. M. tnherculata is hermaphrodite, and I am 

 able to add this particular to the definition of the genus given 

 by Erdmann.* I could not make out any regularity in the 

 arrangement of the reproductive elements on the different 

 mesenteries, nor did there seem to be any definiteness in their 

 position in any one mesentery. Sometimes a mesentery would 

 possess ova only, but usually each one presented both ova and 

 spermatozoa. 

 Cortioifera ooellata (Ellis). 



Alcyouitim ocellatum. Ellis and Solander, 1786. 



Palythoa ocellata. Lamouroux, 1821. 



A number of small colonies of a Cortidfera were obtained at 

 Shelly Bay, and were accompanied by a label referring them 



* A. Erdmann, ioe. cil. 



