GENUS DIKAMCEBA— DINAMCEBA MIEABILIS. 93 



nucleus appeared to be a sphere containing large granules of uniform size. 

 The specimen was quiet, remained nearly stationary, and occasionally 

 emitted here and there a small conical pseudopod. In a similar specimen 

 the nucleus presented the appearance of including exceedingly dehcate 

 coiled filaments, but the time did not permit me to investigate further the 

 nature of these. 



Dinamaeha mirabilis, in size, habitual form, and some other characters, 

 approaches Pehmyxa villosa, and after recognizing ^wfl?&a tentaculata as 

 representing another stage of the former, I began to suspect that it might 

 likewise be the same. When, however, we take into consideration the usual 

 abundance of pseudopods in Dinamoeba, their paucity or absence in Pelo- 

 myxa villosa, the difference in the character of the villous and papillary 

 processes, and the difference in habits, with other occasional pecuUarities, 

 we may regard them as distinct unless further investigation shall prove 

 otherwise. 



JDinamoeba mirabilis bears considerable resemblance to Mastigamceha 

 aspera, described by Prof. Schulze.* This animal is broad, fusiform, about 

 0.1 mm. long, provided with many pseudopods and a general investment 

 of minute bacteria-like bodies, but is particularly distinguished by the 

 possession of a long flaipellum, projecting in front, from an ovate corpuscle 

 enclosing a nuclear body. When I first saw the figure of Mastigamceha, it 

 occurred to me th9,t Dinamoeba was the same, and that the flagellum in the 

 latter had inadvertently escaped my notice. I waited rather impatiently 

 until the following season, that I might again have the opportunity of exam- 

 ining what I had described as Dinamoeba. I have since seen an abundance 

 of specimens in a variety of conditions ; but in none did I ever see a 

 flagellum. 



Dinamoeba further differs from Mastigamoeba in other respects : in the 

 habitual form of the body; in the pseudopods, which are digitiform in the 

 latter ; and in the relative position of the minute spiculate bodies investing 

 the animal, which in Mastigamoeba are described as generally placed 

 parallel with the surface. 



Dinamoeba seems also quite distinct from Bactylosphcerimn vitreum of 

 Hertwig and Lesser,! which appears to be related with Mastigama^a aspera, 



* ArcMv f. mikroskopische Anatomie, 1875, 583, Taf. xxxv. 



t Archiv f. mikroskopische Anatomie, 1874, Sup. U, Taf. ii, Fig. 1. 



