2 Porifera. 



^Rauff, H. , 2. ijhcr Polaeosjyonpa prisco. Bornem. , Eophyton z. Th. , Chondrites nntiquus, 



Haliscrites z. Th. und ähnliche Gebilde, in: N. Jahrb. Min. Geol. Pal. 2. Bd. p 92 



—104. 

 , 3. Über den Bau des Stützskeletes bei den Anomocladinen, sowie einiger Tetracla- 



dinen in: Verh. Nat. Ver. Bonn 48. Jahrg. Sitz. Ber. p 33 — 37. 

 Schimkewiisch, AVI., Versuch einer Classifikation desThierreichs. in: Biol. Centralbl. 11. Bd. 



p 291—295. [2] 

 Thiele , J. , Die Stammesverwandtschaft der Mollusken. Ein Beitrag* zur Phylogenie der 



Thiere. in: Jena. Zeit. Naturw. 25. Bd. p 480—543. [2] 

 Topsent, E., 1. Sur la distribution geographique de quelques Microsclerophora. in : Bull. 



Soc. Z. France Tome 15 p 231—233. [4] 

 , 2. Deuxieme contribution ä l'etude desClionides. in: Arch. Z.Exper.(2) Tome 9 p 555 



—592 T 22 F 9—17. [4] 



, 3. Essai sur la Faune des Spongiaires de Roscoff. ibid. p 523—554 T 22 F 1—8. [2] 



, 4. Voyage de la goelette Melita aux Canaries et au Senegal 1888 — 90. Spongiaires. 



in: Mem. Soc. Z. France Tome 4 p 11—15 T 2. [No histology.] [4—6] 

 , 5. Spongiaires des cotes oceaniques de France, in: Bull. Soc. Z. France Tome 16 



p 125—129. [No histology.] [4] 

 Weliner, W., Die Süßwasserschwämme, in: Zacharias, Die Thier- und Pflanzenwelt des Süß- 

 wassers. 1. Bd. p 185—236 F 36 — 46. [Compilation of the principal facts known 



concerning Fre.shwater Sponges.] 

 Wilson, H. V., Notes on the Development of some Sponges. in: Journ. Morph, Boston Vol. 5 



p 511—519 3Figg. [5] 



A. General Works. 



According to Thiele Porifera can be derived from simple Cteiiophora. The 

 very simplest sponges such as Asconidae are still further degenerated. 



Schimkewitsch classifies the Metazoa as Radiata and Bilateria. The sponges 

 (»Spongiaria«) with the Coelenterata belong to the former gronp. Their mesen- 

 chyme developes » Muskel- und Geschlechtszellen a and is therefore not equivalent 

 to the mesenchyme of other animals. The author wishes to call that tissue 

 »Parenchym«. — For the Phylogeny of Porifera, see also infra, Allg. Biologie, 

 Simroth, for the »Plastidules«, ibid. Zoja, for the Symbiosis of Suherites and 

 Pagurus infra, Mollusca p l, Aurivillius. 



Keller (i) describes 42 species of sponges from the Red Sea, 22 of which 

 are new. Altogether [cf. Bericht f. 1889 Porifera p 3] he found 88 species 

 (53 genera). Of these only 8 species belong to the Tetraxonina and 7 to the 

 Calcaria, but 19 to Ceratina and 54 to »Monactinellidaeff ; thus the large majority 

 belong to the Cornacuspongiae. The author states, however, that little more than 

 the littoral zone is investigated. 



Topsent (^) describes HO species from Roscoff, 4 of which are new; 17 belong 

 to the Calcarea and 82 to the Monaxonida ; there are 5 species of Choristida, 

 while Placina, Halisarca, Oscarella, Spongelia and 2 species of Aplysilla complete 

 the list. Reviewing the description of such a wide assortment the author remarks 

 that, while in many the adult form (incrusting, globular, etc.) is a true charac- 

 teristic, others are amorphous — wrongly called »polymorphous« ; true polymorphism 

 he has only seen in Esperiopsis polymorpha Tops, from the North Sea. Colour 

 is an untrustworthy characteristic of species. It is due (1) to a true pigment in the 

 granulär cells of the mesoderm and the flagellate cells, or (2) to reserve granules 

 in the «cellules spheruleuses«, or (3) in littoral sponges, »ä la production, dans 

 leurs parties peripheriques, sous l'influence de la lumiere, d'une substance mole- 



