new or little-hnown Infusoria. 213 



Trochilia marina^ sp. n. (PI. XII. figs. 7-9.) 



Diagn. Corpus ovale, in vertice paululum coangustatum, 

 inferiore parte corrotundatum, dorsi superficie leevi. 



Log. Black Sea, Crimea, Livadia. 



Descr. The slightly compressed body is regularly oval, 

 except the anterior part, which is a little constricted and trun- 

 cated ; the rounded posterior part is furnished with a large 

 and broad movable spine, excavated internally, and directed 

 from right to left. The dorsal surface is more convex than 

 the ventral, which is furnished with a space covered with 

 cilia ; this space is only half as wide as the body itself, and 

 is of a slightly arcuated triangular form. On the dorsal surface 

 there are two grooves, which run the whole length of the 

 body, one on the right, the other on the left side, thus dividing 

 the whole dorsal surface into three equal parts (PI. XII. tig. 8). 

 The single contractile vacuole is situated on the back, a little 

 towards the left side. The oval nucleus is rather large, and 

 situated on the right side. The mouth, with its bacilli, is 

 very visible (PI. XII. fig. 9). 



This species^ which is very well characterized by the form 

 of the body, is not rare in the Black Sea, where I have often 

 found it among the seaweeds covering the stones of the shore 

 of the Crimea, near Livadia. 



The genus Trochilia, first established by Dujardin, was 

 exceptionally characterized by Stein by this peculiarity, that . 

 the cilia are not merely placed at the margins of the body, 

 but occupy a larger or smaller portion of the ventral sur- 

 face. The species hitherto known are a marine species 

 [TrocMlia sigmoides^) found by Dujardin in the Mediter- 

 ranean, and two freshwater species, Trochilia palustris^ de- 

 scribed by Stein t, and T. polonica^ described by Wrzesniow- 

 skij. Besides these three species and the fourth which I 

 have just described, I think I may refer to the same genus 

 another marine form from the Norwegian coast, described by 

 Claparede and Lachmann§, in their '■ Etudes sur les Infu- 

 soires et les Rhizopodes,' under the name of JEgyria oliva. 

 As we may conclude from the excellent figure given of it by 

 Claparede and Lachmann, this form must undoubtedly belong 

 to the genus Trochilia^ the greater part of the ventral surface 



* Dujardin, Hist. Nat. des Infusoires. 



t Stein, Organismus, Abth. i. p. 118, Taf. ii. figs. 28, 80. 



\ Wrzesniowski, " Eeobaclitungen iiber Infusorien aus der Uragebung 

 von Warscliau," Zeitschr. fiir wiss. Zool. Bd. xx. p. 485, Taf. xxiii. fig. 37. 



§ Claparede and Lachmann, ' Etudes sur les Infusoires et les Rhizo- 

 pudes,' p. 289, pi. xv. figs. 14, 15, 



