84 



ON CLASSIFICATION. 



and of contractile vesicles, and, for the most part, with long 

 pseudopodia, which commonly run into one another and become 

 reticulated. 



3rd. That of the Thalassicolhe, provided with structureless 

 cysts containing cellular elements and sarcode, and surrounded 

 by a layer of sarcode, giving off pseudopodia, which commonly 

 stand out like rays, but may and do run into one another, and 

 so form networks. 



Fiff. 38. 



- i> . 



;p3\JLa 





Fig. 38. — Sphcerozoum ovodimare (after Haeckel), one of the Thalassicollcr . 



While a fourth type of structure is probably furnished hy 

 those anomalous creatures, the Acinette, the radiating processes 

 of which serve as suctorial tubes down which the juices of their 

 prey are conveyed. 



That the Bhizopoda are divisible into at least three groups, 

 corresponding to the three first-mentioned types of organiza- 

 tion, seems to me unquestionable ; but it is another matter, and 

 one on which I offer no opinion, what should be the exact 

 limits of these groups, and what denominations we ought to 

 employ for them. And it must be recollected that, so long as 

 naturalists are unacquainted with the sexual method of repro- 



