On the Anatomy and Physiology of some Zoophytes. 385 



great in directing observers in a fruitful path and in exciting 

 important researches, among which we may mention those of Va- 

 lentin, Vogt, Bergmann, Reichert, BischofF, Barry, Lebert and 

 Hcnle. In my turn I shall make known the result of the observa- 

 tions which I have made upon so disputed a subject — observations 

 which during several years have been many times detailed in the 

 course of instruction which I give in the College of France. 



XLIII. — Anatomical and Physiological Observations on some 

 Zoophytes. By John Beid, M.D., F.R.C.P.E., and Chandos 

 Professor of Anatomy and Medicine in the University of St. 

 Andrews. 



[With a Plate.] 



In the following observations upon the structures and actions of 

 some of the Zoophytes obtained from the shore of the bay of 

 St. Andrews, I have confined myself to those points which are 

 either new, or which appeared deserving of additional illustration. 

 In using the terms superior and inferior, upper and lower in re- 

 ference to the relative position of different parts of the polypidom, 

 in the descriptive parts of this paper, the polypidom is supposed 

 to be in the erect position, so that these terms correspond to an- 

 terior and posterior when the polypidom is placed horizontally. 

 In using the term anterior surface, I mean the sui'face on which 

 the apertures of the polype-cells are placed, so that this corre- 

 sponds 'to the upper surface when the polypidom is laid hori- 

 zontally for examination. 



Cellularia reptans. This polype grows in considerable abun- 

 dance close upon low-water mark, on the exposed surface of a stra- 

 tum of clay-slate and conglomerate, interposed among strata of 

 sandstone belonging to the carboniferous series. Growing along 

 with it, but in much smaller quantities, are Cellularia scruposa, 

 Crista chelata, C. ehurnea, Pedicellina echinata, Vesicularia spi- 

 nosa, Valkeria imbricata and Plumularia falcata, none of which 

 have I hitherto found adhering to the surrounding strata of 

 sandstone. 



The polypidom of this polype possesses some structures which 

 as far as I am aware have not yet been described. At the external 

 and upper angle of the cell, and posterior to the two spines at- 

 tached to this angle (PI. XII. fig. 1 a, fig. 2 c, a, b), three of these 

 structures are found*. The uppermost of these is a hollow pro- 

 cess (fig. 2 b), the superior extremity of which is free, looks out- 

 wards and a little forwards, and has an aperture notched on the 



* Part of this process is seen on looking at the anterior surface of the 

 polypidom, as is represented in Plate XII. fig. 3 h. 



