150 ACALEPHS IN GENERAL. Part I. 



The paper of J. McCrady upon the Gjniiiophthahiiata of Cliarleston harbor, 

 published in the Proceedings of the Elhott Society of Natural History in 1858, 

 contains much interesting, and some highly important and novel, information upon 

 the naked-eyed Medusa? of South Carolina, to which I shall have frequent oppor- 

 tunities of referring hereafter. For the present, I shall only allude to the classi- 

 fication he has proposed of the lowest order of the Acalephs. He is the first 

 naturalist who has adopted the order of Hydroids with the limits I have assigned 

 to it ; but he has introduced a new arrangement of the minor groups. 



CLASSIFICATION OF THE HYDROIDS BY J. McCRADY, 1858. 



1st Sub-order. Endostomata. 



1st Family. Coryniihp. Oceaniila': Oceania, Turritopsis, Tiirris, Modeeria, SapUenia. 

 Sarsiad;t : Sarsia, Coryiiili?:, Dipurena, Slabberia. 

 Clavida; : Clava. 

 2d F.amily. VelelUdtr. Yelella, Porpita, Chrysumitni, Rataria. 

 3d Family. Tubulariilti', 



Peniiarida' : Cladunem.a, Zanclea, Pennaria, "Willsia. 

 Tubularida' : Steeiistruppia, Eiipliysa, Tubularia, Corymorpha. 

 IIippocrenida> : Nemopsis, Lizzia, Bougainvillea, Ilippoerene, Cyta?is, 

 Eudcndriuin, Ilydractinia. 

 4tli Family. Sipliomipltoro'. 



Physophorida; : Forskalia, Agalma, Agalmopsis, Pliysophora, etc. 

 Ilippopodida' : Hippopodius, Vogtia. 

 Dipliyida': Prayia, Diphyes, Eudoxia, etc. 

 Plijsalidaj : Physalia. 

 ■2d Sub-order. ExosTO\rATA. 



1st Family. Caiiipatmlarida;. 



Thau man t iada> : Thaumantias, Staurophora, Tiaropsis. 

 Eucopida' : Geryoiiopsis, Tiraa, Euco]ie, Euclieilota, Eiienthesis, Cam- 

 p.anularia. 

 2d Family. Sertularidcp. Sertulnria, Ilaleeium, Tliuiaria, Plumularia, Aglaophenia, Antennularia. 

 Clrceada:. Circe, Persa, Aglaura. 

 Tracltyuemidie. Tracliynema, Riiopalonema. 

 3d Family. -[ Slomohracliida-. StDmobraeliium, Mesonema. 

 Geryonida:. (Jeryoiii;!, Liriope. 

 1^ ^Eqiwrlada. ^T2q\iorea, Rhaeostoraa. 

 4th Family. JEgliiida. Cunina, iEgina, iEgineta, -lEginopsis, Polyxenia. 



Besides extensive and valua1;le contributions upon the structure and affinities 

 of the Acalephs in general, published in the Transactions of the Royal Society of 

 London, and of the Siphonophonv in particular, published in Miiller's Archiv, Huxley 

 has lately proposed a new classification of the latter, which he calls Hydrozoa. 



