GENUS DINAMCEBA— DINAMCEBA MIRABILIS. 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 delicate 

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

 nature of these. 



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

 approaches Pelomyxa villosa, and after recognizing Amoeba 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 Dinamceba, their paucity or absence in Pelo- 

 my.ra villosa, the difference in the character of the villous and papillary 

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

 we may regard them as distinct unless further investigation shall prove 

 otherwise. 



Dinamceba mirabilis bears considerable resemblance to Mastigamceba 

 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 flagellum, projecting in front, from an ovate corpuscle 

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

 occurred to me that Dinamceba 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 Dinamceba. I have since seen an abundance 

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

 flagellum. 



Dinamceba further differs from Mastigamceba 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 Mastigamceba are described as generally placed 

 parallel with the surface. 



Dinamceba seems also quite distinct from Dactylosphcerium vitreum of 

 Hertwig and Lesser, f which appears to be related with Mastiyamceba aspera, 



*Archiv f. inikroakopisclie Auatomie, 1875, 583, Taf. xxxv. 



t Arehiv f. mikroskopische Anatoraie, 1874, Sup. .4, Taf. ii, Fig. 1. 



