Genera of the Xorth American Palaeozoic Bryozoa. 409 



covered in the fresh waters near the Hague, a plant-like animal, 

 growing in masses, from which proceeded crescent-shaped ten- 

 tacles. The tentacles were the most striking feature of these 

 animals, and from them Trembley gave the name to the animals of 

 " Polype a panache," the Polyp with plumes. In the Philosophical 

 Transactions for 1742 will be found a full account of this discov- 

 ery, and in " Memoirs pour servir a I'Histoire du genre de Polypes 

 d'eau douce," Leyden, 1744, he gives an accurate account of the 

 anatomical details, which have been surpassed by few subsequent 

 observers. He demonstrated an alimentary canal, consisting of 

 oesophagus, stomach and intestine, and also the muscles. He. also 

 showed the relation between the animal and its cell, and proved 

 that the latter was created by the former. He further described 

 and fully understood the statoblast. Though recognizing the in_ 

 testine, he failed to detect its termination. 



This species was subsequently found in England by Bakek, 

 who gave to it the name " Bellflower animal " in " Employment 

 for the Microscope," 1753. In this paper is first recorded the 

 termination of the intestine. 



In the autumns of 1741 and 1742, Beritard de Jussieu and 

 Guettard visited different points on the coast of France for the 

 purpose of studying the marine zoophytes. They had an oppor- 

 tunity of observing several forms, which had not been seen by 

 Peysonnelle, notably Sertularta, Flustra and ALcroNiuM, the 

 last of which especially excited their admiration by the beauty 

 of its tentacles which could be seen by the naked eye. Lamarck 

 speaks very highly of Gcjettard's labors, which seem to have 

 been especially directed to fossil Polypes and Sponges. 



The result of the observations of Jussieu was communicated to 

 the tioyal Academy of Sciences on the 14th of E'ovember, 1742, 

 and was published in 1745. His observations were precise and 

 were illustrated by excellent figures. He described four species as 

 illustrating the most remarkable forms, viz.: Alcyonium digita- 

 tum, Tubulariaindivisa^ Flustra foliaceadin^ Cellejpora jpumicosa. 

 In regard to the Sertulirid^ in the Mem. de I'Acad. Royal des 

 Sciences, 1742, he says, "II s'en presentoit ensuite quantite des 

 celles qu'on appelle Corallines, les unes pierreuses dans lesquelles 

 je ne remarquai rien, et les autres dont les tiges et les branches, et 

 52 



