M.'F/Miiller on the Systematic Position of the Charybdeidi'fc. 7 



It is otherwise, however, with the family of the Charybdeida, 

 which Gegenbaur arranged with his Acraspeda, the Phanero- 

 carpse of Eschscholtz. Chary bdea marsupialis, Peron, and still 

 more Tamoya haplonema and T. quadrumana, described by me, 

 are opposed most decidedly in almost all the essential features 

 of their structure to the above general picture : a bell with 

 deeply furrowed sides and a broad velum, scarcely capable of any 

 alteration of form; the marginal corpuscles four in number, 

 distant from the margin, in deep niehes of the outer surface of 

 the bell ; a long oral funnel, after the fashion of Thaumantias ; 

 §exual organs in the form of broad membranous laminae in the 

 wide lateral pouches of the stomach, and therefore remote from 

 the stomachal filaments ; tentacles upon peculiar clavate or 

 hand-like processes ; a distinctly marked nervous system, &c. 

 .. In its external form (and this only is known) the Charybdea 

 periphylla, Peron, is almost still more strikingly in contrast to 

 the ordinary Medusa; it" is, as it were, a Tamoya quadrumana 

 with hand-like appendages increased to sixteen in number, and 

 deprived of their tentacles. 



It appears, therefore, scarcely possible to imagine transition- 

 forms between the Chartjbdeidce, on the one side, and the Medu- 

 sida and Rhizostomida, on the other, or even to derive the two 

 groups from a common fundamental form containing essentially 

 anything more than the general features of all Hydromedusa. 

 The intuitively clear picture of Eschscholtz's Phanerocarpa 

 would fade into a shadow by the reception of the Charybdeida, 

 and at any rate their union would be perfectly unnatural. 



And yet, if we will retain the usual bipartition of the Disco- 

 phorous Acalephs, in which the systems of Forbes, Liitken, and, 

 Gegenbaur have altered nothing but the names *, and which 

 even recurs (in respect of the Medusoid forms) when the Disco- 

 phora, and rightly, are no longer recognized as a systematic, 

 unity, as in the Acalepha and Hydroida of R. Leuckart, the 

 Charybdeidce can only find a place among the higher Medusa, 

 with which they have in common at least the stomachal filaments 

 and the insoluble contents of the marginal corpuscles. It can- 

 not be disputed that they are still further removed from the 

 Medusoid brood of the Hydroida. 



On a former occasion, in describing the Tamoya, I already 

 thought of a preferable tripartition of the Discophora, and anti- 



* Not the foundation, or principle of division, as Gegenbaur will have it. 

 Eschscholtz by no means regards the " germ-cushions " as either the sole 

 or most important character of the Phanerocarpfe : he placed, like Gegen- 

 baur, the emargination of the margin in the first rank, and was very well 

 acquainted with " the soft, membranous, annular lobe on the margin of the 

 disk," as the common character of his Cryptocarpae. 



