﻿April, 1857.] 



ELLIOTT SOCIETY. 



133 



which each ovary contains only a few, as they grow, swell the 

 outline of the upper portion of the trunk in large sweeping 

 curves. The whole trunk thus described, appears suspended in 

 the bell-cavity by many radiately converging arches, like one of 

 the massive pendants hanging from a gothic ceiling. The prin- 

 cipal of these arches, (those with double lines,) are the result of 

 the arrangement described in the diagnosis of the genus, by which 

 the radiate tubes, springing from the upper surface of the dark- 

 coloured digestive cavity, proceed, for a short time, in almost hori- 

 zontal direction outwards, then with a bold curve sweep down- 

 wards almost vertically to the ocellary bulb. They nowheres, 

 therefore, reach higher than the base of the digestive trunk. The 

 cavity, however, of the disk is prolonged upwards in four over- 

 arched spaces, between the arches of the radiate tubes, and the 

 outline of these is marked out by the double outline of the epithe- 

 lium clothing the inner surface of the bell, (figure 3, jo.) Above 

 these at q, are two arches of single lines, disclosing a differentia- 

 tion between the tissues in that part of the wall, the immediate 

 purpose, and the homologies of which, I do not undertake at pres- 

 ent to explain. The tentaculiferous margin of the bell is charac- 

 terized by an unusual development of the transparent tissue which 

 always surrounds the faintly-colored marginal tube and the col- 

 ored ocellary bulbs. The bulbs, and the tentacula which they 

 bear, are like the digestive trunk massive. The ocellus is borne 

 in the surrounding clear tissue of the bulb near its upper margin. 

 The shaft of the tentaculum tapers from the marginal bulb to its 

 junction with the clavate extremity, and is ornamented with four 

 or five oblong pads of thread-cells, whose longer axis is placed 

 rather obliquely to the transverse axis of the shaft. These shafts 

 possess considerable contractility, though it is very slow in opera- 

 tion, the tentacula never contracting suddenly to any great extent 

 upon irritation. The shafts, however, may be so contracted gradu- 

 ally by continued stimulus, as to bring all the pads of thread-cells 

 together, thus forming a spiral chain of them round the shaft; and 

 finally the shaft be so contracted as almost entirely to disappear. 

 The enlarged extremity of the tentaculum also partakes, to some 

 extent, of this susceptibility, so that its- usually ellipsoid bulb, 

 (figure 3, c,) is sometimes changed by contraction into an almost 

 spherical ball, (figure 4, c.) 



The specimen represented, figure 4, had but three sexual lobes, 

 the fourth being abortive. At the same time the mouth presented 



