Zoological Society. 295 



scribing a gentle curve. It is hyaline, not very thick, and quite 

 smooth. The central portion of its interior, occupying about one- 

 fourth of its diameter, has dependent from it the membranous veil- 

 like walls of the stomach ; these hang not quite so low as on a line with 

 the margins of the umbrella. The stomach, although equal in width 

 throughout, may be divided into two regions, an upper and a lower. 

 The latter has a furbelowed and somewhat scalloped, but not cirrated 

 margin, and may be regarded as the mouth. The former is marked 

 internally by eight ba ids of transversa fibres, separated by as many 

 longitudinal on?s ; tJiass appear to be muscular. The whole of the 

 membrane of the stomach and lips is] tinged with pale foxy brown, 

 partly disposed in streaks. Around the upper and inner margin of 

 the cavity are the orifices of the gastro-vascular canals ; these run, 

 without dividing or anastomosing, to the circular marginal canal of 

 the umbrella. In a specimen five inches across, they were 136 in 

 number. From the lower side of each canal depend two narrow, 

 rather wavy membranes of a violet colour, causing the ray-like streaks 

 that shine so conspicuously through the disc ; each of these arises 

 gradually near the superior extremity of a gastro-vascular canal, and 

 ceases abruptly at about one-eighth of the entire length of the canal 

 from the margin : they are the genital glands. At the junction of 

 each alternate gastro-vascular canal with the circular marginal one is 

 the bulb-like base of a marginal tentacle : these tentacles arise from 

 ovate bulbs and gradually taper to a fine point. The bulbs are pale, 

 but the tentacle is tinged with violet. Opposite the intermediate 

 canal there is a smaller bulb with a tentacle, hollow and containing 

 corpuscles in its centre, and on each side, between it and the neigh- 

 bouring tentacle, is a still smaller lobe-like body. Along the upper 

 margin of the circular canal are very minute pedunculated organs 

 that move to and fro. On the bulb at the base of the tentacula is a 

 minute tongue-shaped process at the base of a depression ; at its own 

 base the ocellus or rudimentary eye is lodged. When seen laterally, 

 the peculiar tissue of the base of the tentacles is observed to be set 

 obliquely. Within the umbrella, from a line just opposite the ten- 

 tacular circle, a short but rather broad veil with a simple edge is seen 

 to depend ; this veil is tinged with pale brown. A band of motor 

 tissue, forming a sphincter to the umbrella, accompanies the circular 

 vessel. 



According to the size of the example, the number of genital glands 

 and of tentacula varied : they increase with age. The smallest num- 

 ber of tentacula seen was sixteen, and there is reason to believe that 

 they are never fewer. 



To ascertain whether this beautiful animal be the Medusa cequo- 

 rea of Linnseus and the naturalists who wrote during his time, it is 

 necessary to inquire into the history of that species. The name just 

 mentioned occurs first in the ' Iter Hispanicum ' of Peter Loefling, 

 published in 17^)8. In his journal of observations on the 18th of 

 April, at Cumana, he notices, along with Medusa (i. e. Aurella) 

 aurita. Medusa pelagica {Felagia cyanella'^.), and Velella, another 

 Medusa, which he styles jEquoreaj and describes as " orbicularis, 



