﻿140 LEIDY ON THE MARINE INVERTEBRATE FAUNA OF 



sequently by Gosse,* and remain attached to the emptied cells as long extended tubes 

 From the smaller cells the style is also extruded, and then appears as a more expanded 

 portion of the thread, with which it is continuous at one end and with the capsule at 

 the other, as seen in figures 15, 16. An attentive examination of the extruded thread 

 exhibits a more complicated structure than would have been suspected, and as remarked 

 by Agassiz, who first detected the peculiar arrangement, its exact character is exceed- 

 ingly difficult to ascertain and requires the utmost power of the microscope to analyze. 

 In the case of the larger capsules a spiral arrangement is readily distinguishable, ex- 

 tending the entire length of the extruded thread. This arrangement in some instances 

 appeared to me to depend upon minute cilia?, which project at right angles from the 

 thread, and apparently pursue a spiral course, as described by Agassiz, and as repre- 

 sented in figure 13 ; but in other instances, it appeared to me as if the thread during 

 its eversion from the capsule, assumed a spiral course within the portion preceding it, 

 and that the thread externally was encircled at regular intervals with non-vibrating 

 cilise, as represented in figure 14. 



In the case of the smaller capsules the extruded style appears as a tube much dilated 

 beyond its original calibre, narrowed at the extremities, and longer than the cell which 

 contained it, so that it appears to have been folded within itself. From the distal 

 extremity of the stylous tube projects the everted thread, which at times appeared 

 simple, but at other times appeared to possess a spiral arrangement, like the coarser 

 thread of the larger capsules. The tube derived from the style also presents a spiral 

 arrangement, apparently dependent upon long cilise pursuing a spiral course as repre- 

 sented in figure 10, or upon a twisting in the tube as represented in figure 15. 



13. Actinia marginata, Lesueur. Body when contracted, in the form of the segment 

 of a large sphere; when expanded, cylindrical; brown in color with longitudinal 

 bands of brighter brown. Tentacular disk deeply folded, translucent brown. Ten- 

 tacles very numerous, short, elongated conical, from one-sixth to half an inch in 

 length, brown tipped with white, sometimes with a median ring of white, and not 

 unfrequently the white altogether absent. Mouth nearly circular, surrounded with 

 an irregularly lobate, bright orange or reddish brown lip. 



This species is abundant at Point Judith. In one position, beneath an overhanging 

 rock, a short distance from Mr. Hazard's residence, I observed a group in the highest 

 state of development. Some of the individuals measured four inches across the ten- 

 tacular disk. 



Var. ambrea. Attached to fuci I frequently observed small specimens of an Actinia, 

 two or three lines in diameter, and of a translucent ambreous appearance, which I 

 suspected to be the young of A. marginata. 



* The Devonshire Coast. 



