GENUS DIFFLUGIA— D1FFLUGIA LOBOSTOMA. 113 



ditches where other kinds occur. As usually observed, it is seen lying on 

 the side, and it often requires patient manipulation to make it turn in such 

 a way as to obtain a view of the mouth, on the peculiar character of which 

 its specific distinction mainly depends. As ordinarily seen, it bears so 

 close a resemblance with the corresponding views of Difflugia proteiformis, 

 as described and figured by Ehrenberg,* that it may not only be readily 

 taken for the same, but I have suspected that Ehrenberg may have actually 

 had this animal under observation when he described D. proteiformis. 

 Ehrenberg, however, makes no allusion to the character of the mouth of 

 the latter, and subsequently, in referring to one of the varieties of D. lobo- 

 stoma, described by Mr. Carter, first as D. proteiformis, and then, from the 

 trilobate condition of the mouth, as B. tricuspis, he does not even hint 

 that the latter is synonymous with his B. proteiformis. f 



The name of Difflugia proteiformis is exceedingly indefinite in its 

 application. It was originally applied by Lamarck, J without discrimina- 

 tion, to all the forms figured and described by Leclerc as characteristic of 

 the genus Difflugia. § Ehrenberg, attributing the name to Lamarck, applied 

 it to a new form, and ascribed one of the forms represented by Leclerc to 

 the same species. || Dr. Wallich uses the name of Difflugia proteiformis in a 

 sort of generic sense, and regards all other forms of the genus ordinarily 

 recognized as transitional subspecies and varieties.1I 



As previously intimated, Mr. Carter applied the name of D. proteiformis 

 to a species, and subsequently, from the trilobate form of the mouth, named 

 it Difflugia tricuspis.** 



The late Prof. Bailey, of West Point, New York, in his Microscopical 

 Observations made in South Carolina, Georgia, and Florida, mentions the 

 occurrence of D. proteiformis, but gives no clue as to the particular form 

 he viewed as this species.ft 



Ehrenberg's description of D. proteiformis is too incomplete to deter- 

 mine whether it applies to what I have viewed as the D. globulosa of Dujar- 

 din, or the present species, which I have named, from the peculiar character 

 of the mouth, D. lobostoma. I was led to reject Mr. Carter's name of D. 

 tricuspis, evidently applied to the same, as it is objectionable, if we include 



* Infusionstbiercben, 131, Taf. ix, Fig. i. || Infusionsthierchen, 131. 



t Abb. Ak. Wis. Berlin, 1871, 238, 264. If An. Mag. Nat. Hist, xiii, 1864, 215. 



X Animaux sans Vertebres, ii, 1816. **Ibitl. xviii, 1856, 128, 221. 



§ Mem. Mus. Hist. Nat. t. ii, 474, pi. 17. tt Smitbson. Contrib. ii, 1850. 



8 EHIZ 



