46 MARINE ANIMALS OF MASSACHUSETTS BAY. 



on one side or the other, so as to shoot off, sometimes at right 

 angles with its former path. Four large pedunculated eyes, hid- 

 den in the figure by the tentacles, stand out prominently from the 

 circular tube. When the animal is in motion, the tentacles are 

 carried closely curled around the edge of the disk, as in Fig. 

 53, where the Circe is represented under a magnifying power 

 of two and a half diameters. This Jelly-fish is of a delicate rose 

 color, the tentacles assuming, however, a dark-purple tint at 

 their extremities when contracted. 



Lucernaria. (Halyclistus auricula CLARK.) 



One of the prettiest and most graceful, as well as one of the 

 most common of our Jelly-fishes, is the Lucernaria (Fig. 54). It 

 Fig 54 has such an extraordinary con- 



tractility of all its parts, that it is 

 not easy to describe it under any 

 definite form or position, since 

 both are constantly changing ; 

 but perhaps of all its various at- 

 titudes and outlines none are 

 more normal to it than those 

 given in Fig. 54. It frequently 

 raises itself in the upright po- 

 sition represented here by the 

 individual highest on the stem, 

 spreading itself in the form of a 

 perfectly symmetrical cup or vase, 

 the margin of which is indented by a succession of inverted scal- 

 lops, the point of junction between every two scallops being 

 crowned by a tuft of tentacles. But watch it for a while, and 

 the sides of this vase turn backward, spreading completely open, 

 till they present the whole inner surface, with the edges even 

 curved a little downward, drooping slightly, and the proboscis 

 rising in the centre. In such an attitude one may trace with 

 ease the shape of the mouth, the lobes surrounding it, as well as 

 the tubes and cavities radiating from it toward the margin. A 



Fig. 54. Group of Lucernaria; attached to eel-grass ; natural size. 



