HISTORY. 59 



description and figures of the external characters are tolerably good, with the exception of 

 what he says of a kind of collar, which he compares to the iron ferule on the handle of an awl, 

 and represents as surrounding the orifices of the tubes. Rosel has here evidently seen the 

 tentacular sheath in a semi-everted state, in which it presents somewhat the appearance he 

 has described; and believing this to be a permanent character of his polype, has been 

 thus led into error. He has witnessed the currents caused by the tentacular cilia, but has 

 attributed them to water expelled from the mouth. 



A discovery by Rosel of much interest was that of certain little roundish bodies, about 

 the size of the head of a pin, and of a yellowish colour, which, in the month of May, 1754, 

 he found in the water of a neighbouring pond, and which, on being allowed to rest, emitted 

 from various parts of their surface little plumes like those of his " Federbusch-polyp." Rosel 

 has described these little bodies under the title of " Der Kleinere Federbusch-polyp mit dem 

 ballenformigen Korper." They are the young condition of the Polyzoon, for which Cuvier 

 afterwards constituted a new genus, under the name of Cristatella. 



Linnseus's grand invention of a binary nomenclature had now been established, and we 

 accordingly find in the tenth edition of the ' Systema Naturae,' published in 1758, the fresh- 

 water Polyzoa for the first time designated by a generic and specific name.* The " Feder- 

 busch-polyp " of Rosel is here described under the title of Tabipora repens, but with Baeck 

 erroneously referred to among the synonyms. In the 'Fauna Suecica,' 1761, we find the 

 same animal mentioned under the same name.f 



In 1766, Pallas published his ' Elenchus Zoophytorum.'J In this work we have the 

 fresh-water Polyzoa described under generic and specific names, in accordance with the example 

 already set by Linuceus. Under the genus Tubularia, Pallas includes • two fresh-water 

 Polyzoa ; one is the " Polype a Panache " of Trembley, which is now described by Pallas 

 under the name of Tubularia cri/stallina ; the other, the " Federbusch-polyp " of Rosel, 

 described under that of Tubularia gelatinosa. 



In the year 1768, Pallas presented to the Royal Academy of Sciences of St. Petersburg, 

 a memoir on a peculiar production which he had discovered in a lake connected with the River 

 Kliasma, near Vlademir, in Russia.§ It was in the form of large fungoid or spongy masses, 

 and was composed of multitudes of closely compacted tubes, each of which opened upon the 

 surface of the mass by a pentagonal or hexagonal orifice, which allowed of the exsertion 

 of a polypoid body in all respects resembling those of Trembley and Rosel. To his newly 

 discovered animal, Pallas gave the name of Tubularia fungosa ; it is identical with that sub- 

 sequently named Alcyonella stagnarum by Lamarck. The memoir is illustrated by a plate 

 exhibiting the external characters of the Polyzoon, and a magnified but not very correct view 

 of the tentacular crown, and, though quite destitute of anatomical detail, must yet be viewed as 

 an important contribution to the zoology of the day. 



Leendert Bomme, of Flissingen, in 1769, described the tentacular currents in certain 



* LiNN^uSj 'Systema Naturae/ editio decima. Holmise, 1758, vol. i, p. 790. 

 t LiNN^us, 'Fauna Suecica.' Stockholmiie, 1761, p. 537. 



\ Pallas, 'Elenchus Zoophytorum.' Hagee-Comitum, 1766. ^ 



§ Pallas, Descriptio Tubularia; fungosBe prope Volodemirum observatfe. ' Nov. Comm. Petr., 

 xii, p. 565. 



