and on a new Species o/Difflugia. 32^i 



those grains only which are colourless, 4hat character where 

 tlie Dijflugia chooses one particuUir object only for the con- 

 structic^n of its covering. 



The test of this species is even more simple tlian that of -S". 

 scopula ; for among its varieties is the symmetrical hollow 

 dome with a single aperture, passing gradually into that form 

 with more or less crenulatcd interior which simulates the 

 nautiloid one of Foraminifera (to say nothing of the variety 

 of external forms) — at the same time that this early significa- 

 tion might associate it, in a morphological point of view, with 

 the radiated septal divisions of the coral-poly])es. 



I have not been able to see its pseudopodia, for the same 

 reason as stated above for not having been able to see them in 

 S. scopula. Nor have I ever been able to prove that it is or 

 is not locomotive. It certainly adheres firmly to the fucus or 

 object on wdiicli it may be located, but, when fresh, comes off 

 entire by slipping a sharp knife under it, although, in the dried 

 state, as with ^S". scapula^ the body, when broken off, generally 

 (if not always) leaves its disk on the fucus. Schultze's calca- 

 reous ones were locomotive, and thus, by being much smaller 

 and creeping up upon the sides of the glass vessel in which 

 they were kept, no doubt enabled him to see, by transmitted 

 light, their pseudopodia, I could have done the same prolja- 

 bly with S. scopula and S. varians, respectively, if I could 

 have applied a high magnifying-power to them, with trans- 

 mitted light, in their living state. 



AVhat vast numbers of free sponge-spicules of all kinds, 

 fragmentary and entire, there must be floating about at the 

 bottom of the sea, in the Laminarian zone, for these little 

 Foraminifera, both S. scopula and S. varians, to avail them- 

 selves of them so plentifully and so indiscriminately for the 

 construction of their habitations ! 



DiFFLUGIA. 



Having had by me for a year past the description and figure 

 of a new species of freshwater Diffiugia^ it seems not inappro- 

 priate that I should take this opportunity of communicating it; 

 and, from its shape laterally not being unlike that of a plucked 

 goose or other bird of that kind without wings (fanciful as 

 this comparison may be), it may also not be inappropriate to 

 designate it by the following appellation. 



Difflugia bi'pes, mihi. PI. V. figs. 6-9. 



Test oblong, somewhat compressed, expanded posteriorly, 

 narrowed anteriorly (fig. 7) ; lateral view lageniform, with tlie 

 body somewhat inflated (fig. 8) ; posterior extremity obtuse, 



