142 ACALEniS IN GENERAL. Part I. 



There is hardly a branch of Natural History to which Echv. Forbes has not 

 made some valuable contribution. His investigations njjon the distribution of marine 

 animals, as bearing upon the geological changes which have affected their area, 

 have left a permanent impression npou the progress of modern Geology. Among 

 his special zoological studies, the natural history of the Acalephs formed always 

 a favorite topic, to which he constantly returned with renewed interest. His 

 monograph of the British naked-eyed Medusaa contains a sununary of what he had 

 done in that direction up to the year 1S4S. In the preface to this work he pays 

 a just trilnite of gratitude to his friend Mr. McAndrew, to whom he was mainly 

 indebted for the facilities he enjoyed in collecting these materials, and whose 

 name will forever remain associated with that of Edw. Forbes in the memory of 

 naturalists. 



CLASSIFICATION OF EDW. FORBES, 1848. 



Forbes's classification, publislied in Lis "Monograph of the British Naked-eyed Medusaj," relates only 

 to the Discophora?, which he divides into two natural groii|is, corresponding to the DiscophoriK pliane- 

 rocarpic and cryptocarpw of Esclisclioltz, but based upon different cliaracters, not before taken into con- 

 sideration in the arrangement of tlie Acalephs. Tliey are as follows : — 



I. GTMiVOrHTHALMATA. 



1st Family. "Willsiadaj : "Wilsia. 



2d Family. Ocean id. t : Turris, Saphenia, Oceania. 



3d Family. ^Er|uoread;e : Slomobrachium, Polyxenia. 



4th Family. Circoada; : Circe. 



5th Family. Geryouiadw : Geryonia, Tima, Geryonopsis, Thauinantias, Slabberia. 



6th Family. Sarsiad» : Sarsia, Bougainvillea, Lizzia, Modeeria, Euphysa, Steenstnijipia. 



II. Steganophthalmata. Aureha, Pelagia, Chrysaora, Ehizostoma, Cassiopea, Cyanxa. 



MY OWN VIEWS OF THE CLASSIFICATION OF ACALEPHS. 



In a series of lectures, delivered before the Lowell Institute in the winter of 

 1848-1849, a phonographic report of which appeared first in the "Traveller" and 

 afterwards in the form of a separate pamphlet, I have presented my views of the 

 natural afhnities of the Eadiates in general, and there began to trace the homologies 

 of these animals with the other Radiates, and introduced some changes in their 

 classification, which an uninterrupted study for more than ten years longer, along 

 the whole Atlantic coast of North America, from Canada to Texas, has only con- 

 firmed and enlarged by furnishing additional means of comparisons. 



There I circumscribed the type of Radiata in the same manner in which I now 

 think it should be circumscribed, admitting in it three classes onlv, — the Polyps, 

 the Acalephs, and the Echinoderms. There I showed also that the Hydroids are 



