Chap. IL CLASSIFICATIONS OF ACALEPIIS. 131 



The naturalists who have known the Acalephs l)est during the first quarter of 

 this century are unquestionably Peron and LeSneur, and their publications are, to 

 this day, among the most important upon all the members of this class, with the 

 sole exception of the Hydroids. 



CLASSIFICATION OF THE MEDUS.E PROPER BY PERON AND LESUEUR, 1800. 



Thougli Pci'on and LeSiieur have contributed, more extensively tlian any other naturalists of the 

 beginning of this century, to the advancement of our knowledge of the Acalephs, their systematic efforts 

 were limited to the classification of the Medusa? proper, of which they have published the following 

 diagram in the 14th vol. of the Annales du Museum, 1809, 4to. : — 



Premiere division. Meduses agastriques. 

 u. Non pedonculties. 



+ Non tentaculees. Eudora. 

 + + Tentaculees. Berenix. 

 h. Pedonculees. 



+ Non tentaculees. Orythia, Favonia. 

 + + Tentaculees. Lymnorea, Geryonia. 

 Seconde division. Meduses gastriques. 



Premiere section. Gastriques monostomes. 

 a. Non pedonculees. 



+ Non brachidees. 



© Non tentaculees. Carybdea, Phorcynia, Eullmenes. 

 © © Tentaculees. ^quorea, Foveolia, Pegasia. 

 + + Brachidees. 



© Non tentaculees. Callirhoe. 

 h. Pedonculees. 



+ Non brachidees. Non representees. 

 + + Brachidees. 



© Non tentaculees. Melitea, Evagora. 

 © © Tentaculees. Oceania, Pelagia, Aglaura, Melicerta. 

 Seconde section. Gastriques Polystomes. 

 a. Non pedonculees. 



+ Non brachidees. 



© Non tentaculees. Euryale, Ephyra. 

 © © Tentaculees. Obelia. 

 + + Brachidees. 



© Non tentaculees. Ocyroe, Cassiopea. 

 © © Tentaculees. Aurelia. 

 h. Pedonculees. 



+ Non brachidees. 

 + + Brachidees. Non representees. 



© Non tentaculees. Cephea, Rhizostoma. 

 ® © Tentaculees. Cyanea, Chrysaora. 



