76 W. ARCHER. 



When the author's attention was first called to the Sar- 

 codme in question, the object before him appeared hardly 

 more than an accidental globular agglomeration of sand, nor, 

 until this at first sight scarcely noteworthy little mass began 

 to move spontaneously, did he perceive the fine linear pseu- 

 dopodia projectizig around from between the sand particles, 

 and realise the fact that a living organism really lurked 

 inside. 



To judge from the figure and from the author's description- 

 of the mode of motion fixed on the pseudopodia, this form 

 really appears to have the aspect of a heliozoan so encom- 

 passed by foreign arenaceous particles, but on pressure the 

 author found that these did not form a connected test, but 

 were only more or less loosely applied, whilst at same time 

 the sarcode body then assumed the appearance of a discoid 

 or elongate mass ; continued pressure caused the whole to 

 pass into a shapeless commingling of softish finely granular 

 sarcode, with the sand-particles now embedded therein. 



In the ordinary condition the pseudopodia are long (about 

 double the body- diameter), extremely fine, linear, radially 

 extended, rather rigid, and never inosculating ; mostly the 

 foreign particles lie closely applied to each other, allowing 

 no very perceptible interspaces ; but sometimes only a com- 

 paratively few are present (occasionally a few diatom frus- 

 tules), leaving considerable vacant interspaces. The body- 

 mass appears usually to have shown a reddish-colour when 

 closely surrounded by foreign particles, but to have appeared 

 colourless when these were few. But unfortunately the 

 author was unable to gain any insight into the body-struc- 

 ture, not even to discover if it possesses a nucleus. Of course 

 on the result of further investigation in this regard depends 

 the reply to the query as to the proper location of this 

 sarcodine. 



MONOTHALAMIA, 



Under the designation Monothalamia are comprehended a 

 large group of Sarcodina, with such pervading community of 

 structure that no difficulty can be felt in regarding them as 

 forming a related group proceeding from common primordial 

 forms. Hertwig and Lesser after giving at some length the 

 views of the older authors, and a resmne of the gradual 

 growth in our knowledge of their characteristics, and after 

 descanting upon the clearly proven untenability of any real 

 distinction between simple vacuoles and contractile vesicles, 

 formerly regarded as of considerable importance, px'oceed to 

 point out the great distinguishing feature, owing to which 



