Historical Introduction. 



GoLDFuss ') was Ihe first author, who described a species belonging to this di- 

 vision namely Ceriopora gracilis while the first genus Meliceritites has been instituted 

 by RoEMER-) for the three species Mel. gracilis (Goldf), Mel. Roemeri (Hag) and Mel. 

 porosa Roenier. The name Meliceritites is derived from Melicerita, a genus founded 

 by Milne Edwards'') for a fossil species of the present genus Cellularia {Cellaria), 

 Cel. Charlesworthii, and the main character upon which the genus was founded 

 is the arrangement of the zooecia in continuous transverse series, a character which 

 at the present slate of systematic knowledge cannot be regarded as sufficient for 

 the institution of a genus, and therefore the name Melicerita must be regarded only 

 as a synonym to Cellularia. Roemer's genus is defined in the following manner: 

 »Runde Stämme deren sechsseitige Zellen mit einer Ecke und nicht wie bei allen 

 bisher beschriebenen Arten, mit einer Seite nach oben gerichtet sind und die gemein- 

 schaftliche Scheidewand zweier Zellen der höheren Reihe tragend«. After this de- 

 finition he adds the following apparently contradictory information: »Gleiche 

 Zellenbildung findet sich auch bei Eschara und hat Milne Edwards hier darauf die 

 Gattung Melicerita gegründet«. As stated above however it is not the form of the 

 zooecial areas but the arrangement of them in transverse series which has induced 

 Milne Edwards to found a new genus for this species. It is easy to understand 

 that Roemer has derived the name of his new genus from Melicerita as the three 

 species described by him agree with Mel. Charlesworthii in the possession of rhom- 

 bic-hexagonal concave zooecial areas, surrounded by distinct ridges and, besides, 

 arranged in transverse series, and as he has not seen the long tubular part of the 

 zooecia hidden within the colony his only motive to divide Meliceritites from Meli- 

 cerita seems to be the different form of the colony, which in the latter is a two- 

 layered plate while in the former it is ramose with rounded branches. 



v. Hagenow ') is the first author who refers these forms to a special division 

 which he named Salpitigina and characterized in the following manner: »Ange- 

 wachsene verästelte Polypenstöcke, mit langen Röhrenzellen, welche sich kurz vor 

 der Mündung trompetenartig, fast sackförmig erweitern, und äusserlich mit einer 

 kalkigen oder hornagtigen Membran verschlossen sind. In dieser Membran befindet 

 sich die kleine, verschieden gestaltete Mündung, die warscheinlich bei Allen mit einer 

 Klappe versehen war und die bei einigen Arten noch erhalten ist.« At another place he 

 names this >Klappe« operculum: >Ein Operculum ist bei Einigen, vielleicht bei Allen 

 vorhanden«. To this division he refers the two genera Escharites and Inversaria the 

 former of which also comprises Roemer's Meliceritites. Apart from the circumstance 



») 1. p. 35, pi. X, figs 11 a— c. -) 6, p. 18, pi. V, fig. 13. ') 2, p. 34.Î, pi. 12, fig. 19. ^) 5. p. 55. 



