164 Dr. G. C. Wallich on the Type 



that " sometimes Amoeba puts forth a few broad lobated ex- 

 pansions ; sometimes these are more numerous, slender, and 

 elongated, assuming a radial direction ; and occasionally they 

 are so greatly multiplied, radiate with such regularity, and 

 taper so uniformly from hase to apex, as strongly to resemble 

 the pseudopodia o/Actinophrys." 



This is undoubtedly true; and I therefore leave Dr. Carpenter 

 to reconcile the fact with his classification and definitions of 

 the orders, of which I now subjoin a summary, taken from his 

 paper in the ' Natural-History Review ' to which reference 

 has already been made *. 



Dr. Carpenter^ Arrangement of the RhizOPODA. 



LoBOSA. Eadiolaria. Reticularia. 



Ameebina, Actino2)hrt/i7ia. Qromida. 



/'■. AcanthomeU'ma, Foraminifera. 



'■•...'■ Polyci/stina. I 



Thalassicollina. \ 



Infusobia. Gbegabinida. Spongiada. Peotophyta, 



After saying that " any small separated portion of the 

 sarcode body of the Rhizopoda will behave itself after the 

 characteristic fashion of its type" (that oi Arcella behaving 

 like that oi Amoeba,' ili&X of Polystomella, or any other of the 

 Foraminifera, like those of Oromia), and adding that "this 

 fact seems to him to afford an additional justification of the 

 employment of the characters furnished by the pseudopodia 

 as the basis of a systematic arrangement of the class," he in- 

 forms us that the characters of the three orders into which 

 he proposes to distribute its various forms may be concisely 

 summed up as follows : — 



" I. Reticulaeia. — The body composed of homogeneous 

 granular protoplasm, without ayiy distinction into ectosarc and 

 endosarc ; neither nucleus nor contractile vesicle ; pseudopodia 

 composed of the same substance as the body, extending and 

 multiplying themselves by minute ramification, and inoscu- 

 lating completely wherever they come into contact ; a con- 



* It may be well to bear iu mind that the article in the ' Review ' ap- 

 peared in 1861 as an avmit-courier to the ' Introduction to the Study of 

 the Foraminifera,' which appeared just a year afterwards. The tabular 

 classification of the Rhizopods is taken from page 17 of the latter 

 work. 



