﻿Dec, 1856.] 



ELLIOTT SOCIETY. 



61 



sulcus between two of the sexual lobes. When the animal is 

 very young these appear as four knobs or stumps, and, indeed, in 

 the smallest specimen found early in the season, I did not observe 

 them at all. Their borders are furnished with many bunches 

 of thread-cells, which, when the leaf or any portion of it is con- 

 tracted, may be brought together in pairs, or still more crowdedly, 

 and, on its expansion, they may be just as widely separated, 

 giving a considerable variety of appearance to this part of the 

 proboscis. But this is not all, each of these leaflets may be very 

 much elongated and stretched upward along the furrows, between 

 the sexual lobes, so as even to appear on their upper surface, 

 when the animal is looked at' from above. See fig. 2, b, PI. 4. 

 Again, the oral orifice may be exceedingly enlarged, and the leaf- 

 lets so contracted as almost entirely to disappear, a knot of thread 

 cells here and there alone discovering their position. The oral 

 appendages may then be contracted into a puckered row of thread- 

 ceil-bunches, while the orifice of the mouth still remains open as 

 represented, PI. 5, fig. 28b, m. And they may even assume a 

 form similar to that described in the younger specimens. When 

 expanded, the tissue, of which these lips are composed, is of a 

 whitish transparence, with a yellow tinge near their origin, but 

 when contracted, as in fig. 28b, PI. 5, they lose their trans- 

 parency. 



The whole proboscis thus described is capable of limited elonga- 

 tion and contraction. It usually hangs as low as is represented 

 PI. 4, fig. 1, the oral leaflets appearing just a little above the circlet 

 of marginal tentacula. It sometimes seems so far elongated -that 

 the appendages of the mouth are entirely visible without the cavity 

 of the bell, beneath the veil, and, as already mentioned, when the 

 stomach and sexual glands are empty, may be considerably short- 

 ened. It is also capable of flexion from side to side within the 

 bell, as will hereafter be more particularly noticed. See PI. 5, fig. 

 28b. 



It is not at all an unfrequent occurrence, for the thin bell-wall to 

 be much contracted, and gathered in puckers around the upper 

 part of the proboscis, though not so much as figured by Gosse in 

 T. neglecta. A short time afterwards the whole bell may be found 

 entirely reverted, turned inside out, when the thin filmy vail is 

 stretched into such a narrow strip, as not to be recognizable. The 

 contraction of the disk or bell generally takes place when the 

 stomach is full of food undergoing digestion, the animal at that 



