Chap. II. CLASSIFICATIONS OF ACALEPHS. 133 



CLASSIFICATION OF CUVIER, 1817 and 1830. 



It was Cuvier who first separated tlie Acalephs as a distinct class, in the first edition of the 

 '' Regne animal," published in 1817. There he divides these animals into three orders, as follows: — 



1st Order. Fixed Acalephs: — Actinia, Zoanthus, Lucernaria. 



2d Order. Free Acalephs : — Medusa; : Medusa, .3^quorea, Pliorcynia, Foveolia, Pelagia ; Cyanea, 

 Rhizostoma, Cassiopea ; Geryonia, Lymnorea, Favonia, Orythia, Berenice, Eudora ; Carj'b- 

 dea ; Beroe, Callianira, Cestum ; — Diphyes ; — Porpita, Velella. 



3d Order. Hydrostatic Acalephs : — Physalia, Physophora, Rhizophysa, Stephanomia. 



Tlie Ilydroids are referred to the class of Polyps ; and some genuine Polyps, Actinia, and Zoanthus 

 are ranked among the Acalephs. 



In the second edition of that work, published in 1830, Cuvier, excluding now the Actinias from this 

 class, but still leaving the Ilydroids out of consideration, admits the following arrangement for the genuine 

 Acalephs : — 



1st Order. Simple Acalephs: — Medusa, vEquorea, Pelagia, Cyanea, Rhizostoma, Cephea, Cassiopea. 

 — Astomes : Lymnorea, Favonia, Geryonia, Orythia, Berenice, Eudora. — Carybdea. — 

 Beroe, Idya, Doliolum, Callianira, Janira, Alcinoe, Ocyroe, Cestum. — Porpita, Velella. 



2d Order. Hydhostatic Acalephs : — Physalia, Physophora, Hippopus, Capulites, Racemides, Rhi- 

 zophysa, Stephanomia. — Diphyes, Calpe, Abyla, Cuboides, Navicule. 



A glance at the works of Scliweigger is sufficient to satisfy any one that his 

 investigations are to be valued chiefly for their minuteness and accuracy, and that 

 his systematic arrangement of the lower animals is not the result of matured 

 principles, or deep insight into their affinities. 



CLASSIFICATION OF SCHWEIGGER, 1820. 



Schweigger was one of the naturalists who knew the soft-bodied Invertebrates best, during the first 

 quarter of this century. In his extensive journeys on the coast of the Mediterranean, he had collected 

 vast stores of materials to illustrate their natural history, and his " Handbuch der Naturgeschichte der 

 skelettlosen ungegliederten Thiere, Leipzig, 1820, 1 vol. 8vo." is chiefly based upon original investigations; 

 wherefore I allude to it here, even tliough he has done nothing to improve the classification of the 

 Acalephs : but he gives the best summary of their structure for that period. The animals now 

 included in the type of Radiata are referred by him to three classes, — the Zoophytes, the Acalephs, and 

 the Radiata ; and under the last name the Echinoderms are combined with Actinia, Zoanthus, and Lucer- 

 naria. To the Zoophytes he refers the Hydroids and Polyps, with which he also associates Infusoria ; 

 but he judiciously removes from them the Ascidians, which he considers as Mollusks. The Crinoids he 

 rightly regards as Echinoderms allied to Coniatula, and the Corallina; as Alga;. 



The Acalephs are arranged nearly as in the system of Lamarck. 



I. Stephanomia — Physophora — Physalia, Velella, Porpita — Cestum, Callianira, Diphyes, Beroe, 



Noctihica. 



II. Medusa, Lin., and subdivided as in Peron and LeSueur. 



