148 PROCEEDINGS OF THE ACADEMY OF ' [PaRT 1 



assemblage of fine supple threads. These threads have received 

 many explanations. Biitsehli considered them as trichocysts, ho- 

 mologous to those of the Ciliata; Kiinstler as dead pseudopodia; 

 Lanessan as cilia, which are rendered invisible by interposition of 

 mucilage. In my opinion the first of these explanations has the 

 more probability. These thread-like elements, indeed, are only 

 found on dead animals, for if present in life they would not escape 

 observation, owing to the obstacle they would profer to locomotion. 

 We must then look for corpuscles in the body, which would explain 

 the threads themselves. And indeed, in Iron-hematoxyUn prepa- 

 rations siderophile granules are to be found in a moderate number, 

 close under the pellicula, which might eventually be considered as 

 trichocysts not yet exploded. As for an homology with the tricho- 

 cysts of Ciliata there can naturally be none. The whole question, 

 especially that of the significance of these elements, needs further 

 study." 



I have not been able to detect the presence of these special fila- 

 ments, yet must confirm the presence of the siderophile granules 

 of which Belar speaks, and with which we shall soon have to deal 

 more at length. Before going, however, into that particular sub- 

 ject, I must now consider for a time the second form I spoke of, 

 and which was found at Florissant, Ehrenberg's Cryptomonas cur- 

 vata. The diagnosis, as given by this author, is the following: 

 "Monad with a curved carapace, with a very much compressed 

 body, large, twice as long as broad, -jV millimeter in length, anteriorly 

 and posteriorly curved somewhat in the form of the letter S; color 

 green." 



In short, the diagnosis is here nearly exactly the same as that of 

 Cryptomonas ovata; the only difference is in the slight *S-curve, and 

 one can easily understand the two forms having been united into 

 one, so much the more since Cr. ovata, with its special characters 

 not found in Cr. curvata, is also sometimes in the form of an S. But 

 there are, really, differentiating characters which we must now 

 examine. The anterior curvature (towards the ventral side), and 

 the posterior (towards the dorsal side) are not of great importance, 

 yet it must be observed that the curvature was present in all the 

 specimens at Florissant, though it was exceptional in the other 

 localities. The ectoplasmic colorless pelHcle was thicker, and the 

 small globular bodies (siderophile granules) were more numerous, 

 more distinct also, the chromatophores, curved behind, were more 

 distinctly separated from each other. But there are two more 



