208 Dr. L. Plate on Asellicola digitata. 



have not been found in Eliizopoda ; and this circumstance is 

 in favour of the old theory to which I have here endeavoured 

 to give further support. 



Lastly, it may be mentioned that in the process of conju- 

 gation homologies between Acinetse and Ciliata may be 

 demonstrated. In Dendrocometes paradoxus^ for example, as 

 1 have shown in a previous memoir*, the nucleus at the 

 commencement of this process grows into a long filament and 

 then breaks up into numerous pieces, just as is known to be 

 the case in many Ciliated Infusoria (e. g. Paramoscium aurelia 

 &Xidi putrinum) . The Suctorian which will be fully described 

 in the following article displays a further interesting stage of 

 conjugation, which at present can only be compared with a 

 similar one of Paramceciian aurelia. However, we are still 

 too imperfectly acquainted with the conjugation of the Acinetae 

 to be able to dedace genealogical relationships from it. 



EXPLANATION OF PLATE X., A. 



Fig. 1. Acineta Greeffii, from the side. 



Fig. 2. The same, from beneath. 



Fig. 3. The same, two individuals attached to Zootliamnium. 



The letters have the same signification iu all, namely : — N, nucleus ; 

 t, tentacle ; cv., contractile vacuole. 



XXV. — Asellicola digitata, Stein's " gejlngerte Acinete.^^ 

 By Dr. L. Plate f. 



[Plate X., B.j 



The Acineta described in the following pages is a near rela- 

 tive of De7idrocometes paradoxus, St., and lives upon the 

 branchial plates of Asellus aquaticus ; it is generically 

 distinct from all Suctoria at present known, and I propose 

 for it the generic name of Asellicola, in allusion to the place 

 of its occurrence, I have selected the specific name digitata 

 because the distinguished naturalist F. von Stein very clearly 

 described and figured it in his first great publication on the 



• " Untersuchungen einiger an den Kiemenhliittern des Gammarus 

 pulex lebenden Ektoparasiten," in Zeitschr. f. wiss. Zool. Bd. xliii. 

 pp. 175-24L 



t Translated from the 'Zoologische Jahrbiicher, Abth. fiir Anatomie 

 und Ontogeuie der Thiere,' Baud lii. pp. 14.'3-155 (May 1888). 



