BY DR. K. VON LENDENFELD. 137 



In 18G8, two eminent Zoologists, Haeckel (75) and Miklouho- 

 Maclay (76) tried to prove the correctness of Leukart's (1. c.) 

 opinion, that the sponges are Coelenterata. 



Haeckel arrives at the opinion of the Ccelenterata-nature of 

 sponges, by his extensive knowledge of a great many species ; 

 whilst Miklouho-Maclay (1. c.) was brought to this view of the 

 subject by the intensive study of a single form Guancha blanca. 



The most important point in this question, is the fact, that the 

 sponges are developed like all higher animals from ova and Sper- 

 matozoa, and pass through a Gastrula stage, wherefore they must 

 be strictly separated from the Protozoa. 



It is Haeckel to whom the merit of pointing out this simple but 

 all important fact is due. 



Gray (77) published in the same year a classification of the 

 sponges, which has not been accepted by the scientific world. 

 He also describes several new species from Australia. 



Bowerbank (78) criticised Gray's system rather shai'ply, and 

 pointed out many doubtful statements in it. 



In the same year, 1868, appeared 0. Schmidt's (79) third Sup- 

 plement to his Adriatic Sponges, in which the sponges of Algeria 

 are described. 



Some changes are made in the classification and new families 

 are added. 



One of these, the Chalinea, is of interest to us, as nearly half 

 of the Australian sponges belong to it. 



(75). E. Haeckel. Ueber die sexuelle Fortpflanzung und das natiirliche 

 System der Schwamme. Jen. Zeitschr. VI., 641. 



(76). Miklouho-Maclay. Beitrage zur Kenntniss der Spongien I. Jen. 

 Ztschr., IV., 221, aucl Ueber Schwamme des nordlichen stillen Oceans und 

 der Eismeeres. Mem. Acad., Petersbourg, XV., 3. Seite, 1. 



(77). T. Gray. Notes on the arrangement of sponges with the description of 

 oj some new genera Proc. Zool. Soc, 1867, p. 492. 



(78) J. Bowerbank. On Mr. Gray's arrangement of sponges. Proc. Zool. 

 Soc, 1868, p. 118. 



(79). 0. Schmidt. Ill.tes Supplement. Die Spongien von Algier. 



