^nchelia.] infusorial animalcules. 557 



water, and perhaps, says Dr. Ehrcnberg, in the sea (Copenhagen.) 

 Diameter 1 -430th. 



Grenus AciNETA.'^Ty^^ rai/ed little tree Animalcules — This genus > 

 was placed by Ehrenberg, in his great work in 1838, as an appended 

 tribe to the Bacillaria, with which, indeed, its affinities were very 

 slight, and hj-pothetical. In a communication since made, upon 

 the discovery of the genus Dendrosoma, Ehrenberg stated, that Acineta, 

 and the new genus, are allied to Actinophrys, and proposed to include 

 all those three genera with the intimately associated ones, Trichodiscus 

 and Podophrya, in a new family, to be called Acinetina, ranging 

 itself between Bacillaria and VorticelUna. In accordance with these 

 views, the genus Acineta is transfeiTed from its former place to the 

 present. 



The genus Acineta is especially characterized by having a mem- 

 branous lorica, a simple pedicle, and numerous retractile, non- 

 vibrating tentacula. 



In A. Lynghyei, and A. mystacina, Ehrenberg describes stomach- 

 cells ; and in A. tuherosa and A. mystacina, a seminal gland. Self- 

 division not observed. 



The recent elaborate researches of Dr. Stein, have rendered the 

 existence of Acineta, as an independent genus and organism, exceed- 

 ingly doubtful ; and go to show, on the other hand, that Acineta is 

 but a transitional stage of development of Vorticella, Vaginicola, and 

 Mpistylis. (See the account of these genera, and P. 22.) 



A. Lynyhyei. — Lorica spherical, pedicle thick. It resembles a 

 stalked ^c#mo/;/w?/s, while the circular, radiating, pale yellow coloured 

 body, with its thick crystalline stalk, is similar to a retracted 

 Vorticella. Pound on Polj^pes, as Sertularia. Length, including 

 stalk, 1 -100th to 1-1 70th. 



A. tuherosa ( Vorticella tuberosa, M.) — Lorica triangular, com- 

 pressed ; dilated and truncate anteriorly, with three obtuse tubercles 

 or horns, of which the two lateral are more constant, and furnished 

 with tentacula. Pedicle simple and slender. Size 1-2 10th to 

 1 -100th Found in marsh and sea- water, on Ceramium diax^hanum. 

 (P. 21, f. 3, 4.) 



A. mystacitia {Vorticella, Schrank.) — Subglobose, obtusely horned. 



