Miscellaneous, 399 



The so-called muscles of the Scyphistomes originate neither from, 

 the endoderm nor from the outer wall of the cup, but from funnel- 

 shaped invaginations of the perioral ectoderm into the interior of 

 the septa and folds, into which they extend themselves like tubes 

 and remain hollow. The orifices of these tubes are still present on 

 the young strobila, so that the Jii^st Ephyra appears as the original 

 oral segment of the Scyphistoma. 



Besides the strobila-formation a regular budding of the Scyphi- 

 stoma occurs ; in Cotylorhiza I frequently saw the bud grow forth 

 with the foot foremost, so that its last connexion with the parent 

 animal was at the mouth. 



From these observations, made throughout on intact living objects 

 and upon the finest sections, the following deductions may be 

 drawn : — 



a. The coelogastrula of the Scyphomedusse investigated is a 

 secondary embryonic form, as the gastrulation is effected by the im- 

 migration of the endoderm into the cavity of the ccelohlastula. 



b. The Scyphistoma is a perfect Anthozoon. In favour of the 

 close relationship of these two forms only the gastral folds could 

 hitherto be cited ; but these also occur, although imperfectly, in 

 Hydroids, and therefore were not thoroughly decisive as to this 

 relationship. The invagination of the ectodermal cesopJiagus observed 

 by me and the gastral sacs and septa surrounding it, however, stamp 

 the Scyphistoma as a true Anthozoon. 



c. As the strobila is produced only by simple division, and the 

 Ephyra originates under certain circumstances, even without divi- 

 sion, directly from the Scyphistoma, every ground for the assumption 

 of an alternation of generations in Aurelia and Cotylorhiza is re- 

 moved. The Ephyra, and consequently the Scyphomedusa, is a meta- 

 7norphosed Scyphistoma or Anthozoon, just as the Hydroid Medusa is 

 a metamorphosed Hydroid Polyp. — Zoologischer Anzeiger, no. 205, 

 Oct. 5, 1885, p. 554. 



On the Original Fundamental Numbers of Medusce and Echinoderms. 

 By WiLHELM Haacee. 



Hackel founds his genealogical tree of the Echinodermata, in 

 which he adopts the Asterida as the ancestors of the other Echino- 

 dermata, upon the circumstance that in the Asterida there are 

 species with a variable number of arms and others with a con- 

 stantly augmented number, while the same thing does not occur in 

 the other Echinodermata, those " worshippers of the number five," 

 with the exception of the Ophiurse, which, according to Hackel, are 

 nearly related to the Stellerida. 



I have now to state that I have found four quaternary examples 

 and one sextenary one in a South-Australian species of the Echinid 

 genus Amblypneustes. Whether similar specimens have been 



