274 



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 pedimculated 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 pecuhar 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 eequo- 

 rea of Linnaeus 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 1758. In his journal of observations on the 18th of 

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

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

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

 planiuscula, tentaculis plurimis ex margine inflexo, branchiis nullis." 

 This notice, which occurs at page 105 of the Swedish edition of his 

 ' Travels,' is the entire original foundation for numerous references in 

 after-authors. Linnseus, in the first instance, adopted Loefling's name 

 and brief record, which, when read with our present knowledge of 

 Acalephce, barely indicates the genus to which the animal observed 

 probably belonged. In 1775, the descriptions and figures of animals 

 observed during his journey to the East by the lamented Forskal were 

 published under the superintendence of Carsten Niebuhr. Among 

 them was a representation and description of a Medusa, referred to 

 the cequorea of Linnseus, both excellent, as indeed may be said of all 

 that Forskal did. In 1776 a Medusa cequorea was noticed, scarcely 

 more than by name, in the ' Zoologiae Danicse Prodromus ' of Otho 

 Frederic INIiiller. In 1 780, Otho Fabricius, in his excellent ' Fauna 

 Groenlandica,' gives a shorter accomit than usual with him of a Me- 

 dusa, which he refers to the cequorea of Linnseus. He speaks of it 

 as a very simple animal, smaller and softer than Medusa aurita, con- 

 vex above, concave beneath, with very much inflected margins and 

 white marginal cilia. The two last-mentioned characters are opposed 

 to the notion of Medusa cequorea, as represented and described by 

 Forskal, and the first of them to the slight idea of its shape that we 

 gather from Loefling. In 1791 Adolph Modeer commenced the work 

 of hair-splitting by separating the animal of Forskal, under the name 

 of Medusa patina, from that of Loefling, for which he reserved the 



