MEDUSAE. 743 



food of the Cydippe. The vitality, or perliaps the irritability, of the cilia is very enduring, 

 for they continue to act when the animal is cut into several parts, or even when a little 

 piece is nipped oft* and will carry the severed portions through the water quite merrily. 



The development of the Cydippe is very interesting, the young being produced from 

 minute vesicles, and passing through a series of stages before they assume their perfect 

 form. 



IF the reader will now refer to the illustration on page 740 he will see a long, flat, riband- 

 like creature edged with a delicate fringe of cilia. This curious being is called VENUS' 

 (Jut OLE, and from its beauty fully deserves the name. 



This lovely creature is found in the Mediterranean, where it attains to the extra- 

 ordinary length of five feet, the breadth being only two inches. Eightly, the words breadth 

 and length ought to be transposed, as the development is wholly lateral. The mouth of 

 the Venus' Girdle may be seen in the centre of the body, occupying a very small space in 

 proportion to the large dimensions of the creature to which it belongs. A very good idea 

 of the appearance of the Venus' Girdle may be obtained by supposing a Cydippe two 

 inches in length to be flattened and rolled out into a riband of five feet in length. 



Owing to the great length and tenuity of this creature, it is seldom found quite 

 entire, but it seems to care little for the loss of a foot or so of its substance. 



WE now come to a very large order of acalephs, including all those beings which are 

 so familiar under the title of JELLY FISHES, SLOBBEKS, and similar euphonious names. 

 They are all united under the name of Discophora, or disc-bearers, because they are 

 furnished with a large umbrella-like disc, by means of which they are enabled to proceed 

 through the water. 



Each order is separated into several tribes, the first of which is termed Gymnophthal- 

 mata, or Naked-eyed Medusse, because the little ocelli, or eye-specks, are either uncovered 

 or altogether absent. The edge is either simple or branched. The name of Medusse is 

 given to these creatures on account of the long trailing filaments which depend from them 

 bike the snaky locks of Medusa from her head. In the Naked-eyed Medusse, the circulating 

 vessels may be seen radiating to the edge either simple or branched. 



The little figure in the upper left-hand corner affords an example of the family 

 Sarsiadse, which contains several genera found in British seas. All the Sarsise are pretty 

 little creatures, and may be known by the four simple nutritive vessels and the egg-tubes 

 placed in the footstalk. In this genus the umbrella is nearly hemispherical, and there are 

 four tentacles set at the ends of the radiating vessels. 



Though small, the Sarsise are interesting to the naturalist, on account of the curious 

 method by which the young are produced, sprouting like buds from the footstalk, and 

 presenting a very strange aspect as they project in different stages of development. In 

 their first stage, the young Sarsise are nothing more than simple prominences upon the 

 surface of the footstalk, and gradually increase in size, developing first one part and then 

 another, until at last the little creatures are quite perfect, shake themselves free from the 

 parent, and commence an independent existence. 



There is a curious species of this genus, Sarsia prolifera, in which the base of every 

 tentacle is supplied with a little bunch of young Medusse, some just making their first 

 appearance as mere lumps of gelatinous substance, some half-grown, and others nearly 

 ready to free themselves from the parent stock. 



The last figure in this illustration is an example of another family, known by the 

 branching vessels. In this genus the umbrella is rather more globular than in either of 

 the preceding cases, and the vessels are six in number, each being twice divided into two 

 smaller vessels. The footstalk is short. 



THE members of the next family are known by their flattened discs and the egg-tubes 

 running linearly along the vessels. The left-hand figure represents a rather curious genus 

 which is devoid of footstalks and appendages, and has a disc almost as flat as a biscuit. 

 The simple radiating vessels are well shown in the illustration. The right-hand figure 



