SARSIA PROLIFERA. 69 



4. Sarsia prolifera, Forbes. 

 Plate VII, Fig. 3. 



Equally remarkable with the Medusa I have just described is that now before us— indeed 

 more so, for the last was an instance of gemmation from the peduncle, a phenomenon, as we 

 shall hereafter see, previously discovered by Sars in another genus {Zisssia) ; but in Sarsia 

 prolifera we have gemmation from the tentacular bulbs, an entirely new and most remarkable 

 mode of reproduction. 



On the 21st of August, 1846, we found great numbers of minute Medusae in Penzance 

 Bay. Among them was one which, whilst it presented the simple cylindrical proboscis and 

 four tentacula of a Sarsia, differed from all the members of that genus hitherto seen, in having 

 at the base of each tentacle a supplementary bulb, or a bunch of little tubercles suspended 

 like a bunch of grapes. Fortunately, individuals of this curious little creature — it is even less 

 than the last species— were plentiful, so that we were soon enabled to unriddle the anomaly 

 by a careful examination of numerous specimens under the microscope. The supplementary 

 bulbs and grape-like tubercles proved to be young Sarsice, sprouting by gemmation from the 

 bases of the tentacula. 



The Sarsia prolifera is a very dehcate Uttle animal, so faintly coloured as to be incon- 

 spicuous in the water, in that respect differing from the other members of its genus. 

 Its umbrella 'is campanulate, and somewhat inclined to a sub-globose form, smooth, and 

 colourless. 



The opening of it is quadrangular, the spaces between the angles curtained by a veil, the 

 angles themselves bearing each a pale yellow tentacular bulb, marked with a minute black 

 ocellus. From the four bulbs spring as many pale yellow, monihformly-granulated, slender, 

 coiling tentacula. The sub-umbrella occupies about two thirds of the length of the umbrella, 

 and to about a third of its length is suspended the pale yellow tubular peduncle, which is very 

 changeable in form, sometimes inflating itself into a bottle-shape, but apparently never 

 protruded beyond the umbrella. Its summit projects slightly above the sub-umbrella ; its 

 orifice is round, and bounded by a highly contractile rim of fibrous cells. 



In every specimen we found a different arrangement or degree of development of the 

 little buds at the bases of the tentacula ; and not only did each individual differ from the 

 other, but rarely were the arrangements of the germs at the bases of the four tentacles alike 

 in the same example. I have accordingly figured the four bunches of a single specimen to 

 show how they differ, and what the nature of the curious bud-like bodies is. 



In fig. 3, e, all the buds are in a low state of advancement ; the bulging above the 

 coloured ocellus indicates the lowest and most rudimentary stage, corresponding to the wart- 

 like condition described in the account of the buds in the peduncle of Sarsia gemmrfera. 

 To the left of the ocellus, a bud more advanced, and exhibiting traces of an interior cavity, is 

 seen, and dependent from the bulb at its right side is a gemmule already presenting traces of 

 lobation. In fig. 3, g, these two stages are repeated, with the advance in one that four 

 dark masses of pigment-cells indicate the bases of the rudimentary tentacula, and the formation 

 of oceUi. In fig. 3, h, whilst two pf the gemmae are rudimentary, a third shows not only 

 ocelli, but the tentacula distinctly in course of formation, as yet, however, folded in. In 3,/, 



