12 



na, and also on the beaches south of Savannah, in Georgia, upon 

 Warsaw Island. 



Halcyonium. 



The genus Halcyonium is usually spelled Alcyonyum, but this is 

 incorrect. 



I am not aware that any species of this genus has as yet been 

 noticed upon the shores of the United States. In August, 1847, I 

 dredged, however, a very handsome specimen, off Cape Cod, belong- 

 ing to this type. It was attached to a loose shell of Mytilus Modio- 

 lus, upon the concave side of the shell, and seemed to differ from the 

 known species of that genus, in having a proportionally small body, 

 from which rose a cluster of long tubular individual polypi, each of 

 which was nearly as long as the greatest diameter of the common 

 base, from which they arose. When fully expanded, the individual 

 polypi were tubular, cylindrical, slightly contracted under the tenta- 

 cles, which spread in the form of an octagonal star, the lobes stretch- 

 ing slightly outside, and somewhat arched and downward. The form 

 of each tentacle was conical, with a rounded tip; the lobes of the 

 margin were proportionally not very deep ; the odd terminal lobe 

 larger than the lateral ones, the relative size of which was gradually 

 less from the tip of the tentacles to its base. The mouth was slight- 

 ly oblong, without folds, and below it hangs a cylindrical main 

 digestive cavity extending for about one-fourth of the whole length 

 in the expanded state of the tube, but occupying nearly one half of 

 its length when distended by food in the contracted state of the 

 animal. 



The main cavity of the body is subdivided by eight prominent 

 folds into as many imperfect partitions, shut from each other in the 

 region of the stomach by their adherence to its outer surface. The 

 substance of the body is rather consistent. The main bulk, from 

 which the individual polypi arise is especially tough, being supported 

 by numerous calcareous spiculse, spread irregularly through its mass ; 

 but even the individual polypi are of tough substance, less moveable 

 than those of Renilla, and expanding and contracting very slowly, 

 while the polypi of Renilla are rather active. In consequence of 

 this toughness of the substance, it was rather difficult to ascertain 

 the internal arrangement of the parts, and to trace the circulation 

 within the main cavity. I could however, satisfy myself that there 

 are four ovarian bunches hanging from the inner projecting margin of 



