new or little-hnown Infusoria. 217 



5tli July, 1876 ; at this spot I met with it in great abun- 

 dance attached to the Hydroid Lei^toscyjihus Oriqoriewij 

 Mereschk. 2. The shore of Terski, in 66° 58' N. lat. and 

 41° 20' E. long., at a depth of 16 fathoms, on a bottom of 

 gravel and shells. 



Acineta Saifidce is a good species, easily distinguishable 

 from all other known marine species. To show better the 

 affinities of this species and the characters which distinguish 

 it from the others, however, I am under the necessity of giving 

 a short revision of all the marine species belonging to the 

 genus Acineta. With those that I have just described there 

 are in all ten of them, as follows : — 



1. Acineta tuber osa, Ehr. 



2. A.jiatula, Clap. & Lachm. 



3. A. cucuUus, Clap. & Lachm. 



4. A. cothwnia, Clap. & Lachm.* 



5. A. compressa, Clap. & Lachm. 



6. A. divisa^ Fraipontf. 



7. A. crenata, Fraip.| 



8. A. vorticelloi'des, Fraip.§ 



9. A. Iwadiana, Mereschk. 

 10. A. SaifulcBy Mereschk. 



Of these ten species we have four {Acineta 'patula^ cucullusy 

 compressa, and Saifulai) which characterize the northern 

 seas, such as the White Sea and the seas of the Norwegian 

 coast. One species {A. livadiana) is characteristic of the 

 southern seas (Black Sea). The other species are in part 

 peculiar to the seas of the middle of Europe, in part more or 

 less cosmopolitan [A. tuberosa). In comparing Acineta Sai- 

 fulce, with the other marine species it is necessary in the first 

 place to exclude all the species with the bottom rounded, such 

 as A. cothuryiia, Clap. & Lachm., A. compressa, C. & L., and 

 A. livadiana^ Mereschk. ; then among the rest, all having the 

 conical form of the carapace, there can be no question about 

 the following species — A. tuberosa, Ehr., and A. compressa^ as 

 having the body strongly compressed, A. cothurnia, C. & L., 

 and A. cucullus, C. & L., the former having the margin 

 divided into angular lobes, after the fashion of Acineta mysta- 



* Etudes snr les Infusoires et les Rhizopodes, p. 588 ; and Stein, Infus. 

 p. 224, pi. iii. lig. 36. 



t Eecherclies sur les Acinetiens de la cote d'Ostende, 1878, p. 25, 

 pi. ii. fig. 1, &c. 



X Fraipont, I. c. p. 89, pi. vi. tig.s. 1-11. 



§ Fraipont, l. c. p. 92, pi. vi. tigs. 12-17. 



