274 Prof. E. Ehlers on the Interpretation 



imperfectly differentiated stock. We should adopt his view 

 if we ascribe to this creature the possession of numerous 

 buccal apertures and deny it tentacles. But then the animal 

 remains quite isolated in the circle of its allies, and even as 

 compared with Mreandrina. 



In my opinion Polyparium is a tentacuHgerous but astoma- 

 tous simple animal. This different view rests upon the fact 

 that I cannot adopt Korotneff's notion and regard the cones 

 with their apical apertures, which stand upon the upper sur- 

 face of Polyparium, as buccal cones with buccal apertures. 

 I am well aware that in anthozoal polyparies non-tentaculige- 

 rous personge occur in many forms which may become degraded 

 almost into simple pores ; but to transfer such a conception 

 to the elevations in question on the surface of Polyparium 

 seems to me inadmissible, considering the position which 

 these structures occupy, with relation to the internal spaces 

 separated by septa, in the gastral cavity of Polypariur)i. I 

 regard these cones rather as tentacles having a large aperture 

 at the apex, and deny to Polyparium the possession of any 

 buccal aperture, gastral tube, or central gastral cavity. But 

 this absence of a buccal aperture must be taken only in a 

 morphological sense, as I have no reason for disputing that 

 possibly the apertures at the apex of the tentacles in this 

 animal may be mouth-orifices or apertures of inception. From 

 the investigations of R. Hertwig * upon different groups of 

 the Malacodermata we are already acquainted with a similar 

 reduction of the tentacles in the Hexactinige and Paractinige, 

 so that in the Liponemidee [Polystomidium and Polysipho- 

 nium), the Sicyonidse (Sicyonis), and the Polyopidge [Poly- 

 opis) these structures ai-e so modified and widely opened at 

 the apex that they exactly resemble the '' buccal cones " of 

 Polyparium ambulans ; and yet Hertwig is quite inclined to 

 admit that inception of nourishment occurs through these 

 wide terminal openings of the tentacles. 



But if these " buccal cones " of Polyparium ambulans are 

 tentacles, their position with relation to the " internal cham- 

 bers," to the internal cavity of the animal chambered by 

 septa, may be shown to be in agreement with the normal 

 conditions of an Actinid, so soon as we admit the interpreta- 

 tion of Polyparium as an astomatous Actinid and carry it out 

 in detail. 



Then, however, arises the double question : — On what part 

 of the polyparium are we to place the lost mouth and the 

 parts surrounding it? and to what processes is such a lipostomy, 



* Report on tlie Scientific Results of the Voyage of H.M.S. ' Chal- 

 lenger,' Zoology, vol. yi. (1882), Actiaiaria. pp. 63, 97, 101. 



