110 G. LINDSTRÖM, HELIOLITIDJS. 



of conopactly united baculi, not at all showing the spongy texture of the Perforata. 

 Taking in consideration the constant and distinctive character of all the corals of this 

 group to have twelve septa, it is not probable that Protarfea Verneuili (Hist. Nat. Cor. 

 III, p. 185) with its twenty septa belongs to this genus, nor to this family. When the 

 authors just cited write »portant aux angles de la plupart des calices de petites pointes 

 saillantes», they must mean the rounded warts which are so prominent during the first 

 stages of the growth of this coral and in the mature polypary are faintly discernible on 

 the dividingwalls between the calicles and not only in the corners. 



Nor can I find any reasons with Rominger and Ferd. Roemer^ to see affinities with 

 the protean Thecia. There are no communicating pores between the calicles nor are there 

 any vestiges of tabulaa as they and also Sardeson" pretend. The figures 20, 22, pl. xii 

 present the true aspect of the interiör structure. 



As to Seebach's Styla-raga the foUowing remarks may be given. Even if the species 

 named Styl. Roemeri by von Seebach^ is to be maintained as an independant species, 

 the generic denomination must be entirely abolished on the following grounds. 



In 1851 MiLNE Edwards and Haime had already established'* a genus Stylanva 

 amongst the Poritidae for a singie recent species, Stylarsea Mulleri, quite different, even 

 geuerically, from the palseozoic fossil. But already in the same year (1851) they abolished^ 

 this genus and registered it as a true Porites, identifyiug their Styl. Mulleri with the 

 Linnean Porites punctatus. Seebach seems not to have been aware that the name he 

 gave Ms new genus had been already preoccupied and again cancelled. In consequence 

 it must for ever be kept in disuse. 



As to the fossil itself, described by Seebach as Stylarsea Roemeri, I have been 

 enabled, through the kindness of Professor von Koenen, to examine bis original specimen, 

 which belongs to the Roy. geological-palaäontological Museum of the University of Göttingen. 

 It is figured anew, partially, on the plate xii, tig. 24. It is a thin lamina, scarcely two 

 millimeters in thickness, with a finely wrinkled epitheca. It is to be borne in mind, that 

 the superior surface with the calicles is much corroded by weathering, so that it is im- 

 possible to detect a singie fresh or intact calicle. In all particulars it may, for the rest, 

 be compared with Protaroäa vetusta (fig. 19) having like this species twelve tuberculate 

 septa, a flat or slightly convex area covered with numerous papillie; the only appreciable 

 difference being that the walls of the calicles are a little broader. There is not the 

 »schwammige Columella», which Seebach thought he saw, but the uppermost pointed tops 

 of the columnar baculi, which fill the centre of the calicle, quite as in Protara^a or in 

 Coccoseris. As to the points (»Zacken») in the corners of the calicles, there are several 

 such almost everywhere on the thecae. The spongious tissue of the coral, which should 

 unite it with the recent Litharaea^ is only seeming, owing to the highly corroded surface. In 



^ Lethsea geognostica, 1"^ Theil, p. 455. 



2 Tabulaten, p. 300. 



^ »Die Zoantharia perforata der Palseozoischen Periode» in »Nacbrichten von der Kön. Gesellschaft der 

 Wissenschaften zu Göttingen» 1866, p. 238, and in »Zeitschrift der deutschen Geol. Gesellschafts 1866, p. 305, 

 Taf. IV, fig. 2. 



* Polyp. terr. paloBoz., p. 143. 



^ Recherches sur les Polypiers. »Monographie des Poritides» in Ann. Se. Nat., 3"" Sér., vol. 16, p. 30. 



