16 INTr. H. J. Carter on Astasia. 



means of taking in crude food for digestion in the latter, ai'e 

 distinguishing characters which at once place Astasia limpida 

 on the animal, and Euglena on the vegetable side, respectively, 

 of the great organic kingdom ; yet both Ehrenberg and Du- 

 jardin have classed Astasia and Euglena together. 



In the next place, the genera and species of Euglena are so 

 numerous, that their family name should be "Euglenia," as 

 Dujardin has given them (but not for the reason he has assigned), 

 and not "" Astasiere," as given by Ehrenberg, particularly when the 

 genus Astasia is so imperfectly characterized by Ehrenberg with 

 respect to Euglena, that I believe, with Dujardin, his A. hcema- 

 todes and A.viridis, "in spite of the existence of the red eye- 

 spot, ought to belong to the Euglena ; and the two others, viz. 

 A. flavicans and A. pusilla, if not identical, at least are very 

 nearly allied to Astasia limpida^." 



But Ehrenberg has evidently described and figured Astasia 

 limpida under the name of Trachelius trichophorus-f, of which, al- 

 though "capitate" in respect of the cilium, Dujardin states that 

 Ehrenberg himself observes that he could not see this capitation 

 in the same species when he afterwards examined it in Russia 

 {I.e. p. 355), while Dujardin mentions, in another place, that 

 he suspects Ehrenberg of having described a species of his (Du- 

 jardin^s) Peranema "under the name of Trachelius trichophorus" 

 (p. 354). Thus Dujardin identifies Trachelius trichophorus, Ehr., 

 with his Peranema, which genus, together with his Astasia, he 

 has made the first two genera of his family "Euglenia;'^ pre- 

 mising, however, in his prefatory observations to the subject, 

 that they, with the " IMonadiens," so pass into each other, that 

 " one is liable to place in different genera the different degrees 

 of development of the same animal'^ (p. 349) ; and in his clas- 

 sification, that Peranema and Astasia " are here grouped arti- 

 ficially and after insufficient characters'^ (p. 356). Hence it 

 will not be wondered at that I should have identified Trachelius 

 trichophorus, which Dujardin considers a species of Peranema, 

 with his Astasia limpida. Our respective representations do not 

 exactly correspond, probably for the same reason — that Dujardin 

 had not been able to obtain sufficient characters, as he has stated, 

 for describing this genus ; but he has described sufficient and 

 drawn sufficient for me to make the identification to which I 

 have alluded. 



Lastly, Dujardin, knowing the genus Peranema to take in 

 crude food for nourishment, from his considering Trachelius 

 trichophorus a species of it (for he has also observed that, accord- 

 ing to Ehrenberg, this Infusorium is " voracious'^), has placed it 

 and Astasia among his "Euglenia," which, from the obvious 



* Hist. Nat. des Zoophytes, p. 358. f Ehrenberg, tab. 32. fig. 11. 



