of Invertebrate Animals. 381 



actual observation, it would be useless to characterize it. With 

 the view of assisting in the jjropcr illustration of the animal, I 

 herewith append i\l. Sars's description of Pedicellina. 



The external ajjpearance as well as the peculiar course of the 

 intestinal canal seem to bring this species near to the VorticeUn ; 

 but it is distinguished from these by its distinctly develojjed ten- 

 tacles, which give it a greater resemblance to the Polypi. In fact, 

 it seems to be the link which connects the Infusoria just named 

 with the Polj^i. 



The Pedicellina exhibits itself in the form of several stalked 

 polypi of a sort of gelatinous substance, shooting straight up from 

 a round creeping (t) root. The stem terminates at the top in an 

 oblong, somewhat com])rcssed knob, on the upper end of which, 

 in a hollow, the mouth is found. The hollowed upi)er surftice of 

 this knob forms a sort of edge (or rim) round it, which does not 

 always preserve the same form, inasmuch as it sometimes dis- 

 tends itself to a size greatly exceeding the ordinary thickness of 

 the knob, and sometimes contracts itself very considerably. From 

 this cause proceeds the variety of form which the knob assumes, 

 being sometimes egg-shaped and sometimes cup-shaped. But it 

 is the stem which chielly exliibits the movements of life. When 

 irritated it moves easdy and actively in all directions. PLOuud 

 the upper end or edge of the knob is a single row of cylindi'ical 

 tentacles, the inner side of which is furnished with numerous line 

 and short filaments (cirrhi), which are in almost constant motion, 

 somewhat like the swimming-tilamcnts of the RihbemancEterne 

 {Acalcpha Ctenophora, Eschs.), by which motion a current is 

 produced in the water, and a crowd of the Infusoria which serve it 

 for food are drawn into its mouth or are caught by the tentacles. 

 These last are sometimes thrust out, sometimes di'aAVU in or laid 

 back ; they can also be moved in a variety of ways. 



One of the most singular phccnomena about the Pedicellina is 

 the course of the intestinal canal. It is observed in the interior 

 of the knob proceeding from the mouth do^rawards along one of 

 the small sides, then expanding at the bottom of the knob into 

 an oval shaped stomach, and thence tm-uing upwards along the 

 opposite small side and running back towards the region of the 

 mouth. The mouth and the anus are thus close to each other 

 in the before-mentioned hollow. This formation is interesting and 

 totally different from the Fohq)i, with the exception of the Flustrm 

 and the Corallines which are related to them ; unless indeed we 

 agree with Rapp in excluding these from the Polyps. 



We find in the Pedicellina a striking analogy with Vorticella, 

 according to Ehrenberg's representation of their digestive organs ; 

 but I have never observed a plurality of stomachs. As regards 



