Chap. I. HISTORY OF THE ACALEPHS. 9 



that neither Polyps nor Acalcphs nor Mollusks -will exhilnt their natural appearance 

 when taken out of the element in which they live, it is still to be lamented that 

 both the star-fishes and sea-vn-chins are everywhere represented as they appear when 

 taken out of the water, and all their soft appendages, so numerous and diversified, are 

 drawn in or so contracted and collapsed as no longer to give the slightest idea of 

 their natural beauty.^ Like Aristotle, Rondelet still unites the Actinias and Acalephoa 

 under the name of sea-nettles (Urticas mai'iufe), distinguishing the former as the 

 fixed sea-nettles and the latter as the free sea-nettles. Even Cuvier, in his earlier 

 works, allows these animals to remain together, though it was he himself who sepa- 

 rated them afterwards, for the first time, as members of two distinct classes. Rude 

 as are the illustrations published by Rondelet, it is hardly possiljle to mistake in his 

 fifth species the Rhizostoma of Cuvier, although the disk is too small and the arms 

 too straight, and in the sixth the Chrysaora of Peron, although Linnams refers 

 that figure to the Aurelia anrita. 



In the writings of Aristotle a single part of the Acalephe is distinguished by 

 name, — the mouth, which occupies the centre of the l»ody, of which nothing is stated 

 except that it is fleshy. The passage already quoted from Pliny (Lib. IX. ch. 4o) 

 speaks of leaves ("ac prasnatante pisciculo frondcm suam spargit"), no doubt meaning 

 by frons the thin, expanded margin of the disk, and the ajopendages about the moiith, 

 which he considers as a root (" ora ei in radice esse traduntur"), thus carrying out 

 a comparison of these beings with plants. Rondelet, on the contrary, vindicates 

 especially their animal nature when he says, that since they alternately expand and 

 contract their blade, which serves as feet, and since they absorl) food through the 

 mouth and thus show themselves provided with the senses of touch and taste, which 

 are essential to the animal life, he considers them as imperfect animals, and not as 

 Zoophytes, as Pliny does.^ Speaking of the small sea-nettle, which is his first species, 

 he mentions its short tentacles, and its resemblance to the large intestine, thus dis- 

 tinctly pointing to the genus Actinia, of which, he saj^s, there are several varieties, 

 some green, some Ijlue, some blackish, with IjIuc, yellow, or red spots. His second 

 species seems to be a Tubuliljranchiate Annelid, for he says it bites. His third sjjecies 

 is another Actinia, with which he confounds the ^Equorea of the Mediterranean.^ 



^ In my next Monograph I shall have an oppor- non omuino perfecta, eas numerabimus. Eondeh?tiii#. 



tunity of representing the North American Echi- Lib. XVII. p. 527. 



noderms as they appear in life. ^ It can hardly excite surprise to find, that, with 



- Cum igitur Urticic frondem suam, qua' pedum as little knowledge as Rondelet possessed upon tlie 



vice est, modo dilntent modu contrahant, cum ore subject of Acalephs in general, he should have con- 



cibum accipiant, id est, cum tactu gustuque, qui duo founded a iSIcdusa and an Actinia, especially when it 



sensus ad vitam animalium sunt necessarii, praxlitas is remembered that the numerous radiating tubes of 



sint, non inter Zoophyta, ut Pliuius, sed inter aniinalia the ^Iilquorea give it a greater resemblance to an 

 VOL. in. 2 



