8 ART. 1. r. T.TTMA : HEX ACTINELLTDA, ITI. 



In general shape the present species may be said to be not 

 unlike a Caulophacus sj^ecies, in which the gastral surface, correctly 

 recognized as such, is so turned outwardly and exjiosed as to 

 form a part of the external surface. Indeed, l)y a hurried in- 

 spection of the present species, one might possibly be misled into 

 thinking of the area of the frontal lattice as the gastral surface 

 similarly exposed on the outside. ]^ut the observer will soon see 

 that structurally the frontal lattice is comparable with the dermal, 

 and not to the gastral, layer of Caulophacus, Further, the system 

 of canals communicating with the exterior by openings which I 

 have unhesitatingly called the oscula is completely separate from 

 the other canal-system that leads directly from the space right 

 under the frontal lattice. Unless it be an error to regard the 

 openings just referred to as oscula, the latter canal-system needs 

 but to be considered as incurrent, and it then logically follows 

 that the frontal lattice is a structure calculated to allow the 

 afferent passage of water, which is invarial)ly the character of the 

 dermal latticework. 



The stalk belongs to the back-side of the body ; at any rate, 

 it arises a good distance apart from, and behind, the lower border 

 of the frontal lattice and is covered all over by a direct and 

 uninterrupted continuation of the pith-like surface of the back. 

 Moreover, as before mentioned, it bears a certain number of 

 secondary oscular openings. I lay some importance on the above 

 facts, as demonstrating at once the dermal nature of the back-side 

 surface, since the stalk surface can not possibly be anything but 

 dermal. 



Excepting the soft covering layer, the stalk is firm and 

 compact. It expands above to join the body. It is longitudinally 



