xVlthough insignificant in number, being only two well defined species *), sorae interest is 

 nevertheless attached to the ancient Anthozoa Perforata, burried in the Upper Silurian 

 strata of the isle of Gotland, in consequence of their geological range and their close 

 affinity to Recent corals of the sarne order. Amongst the abundant cylindrical corals 

 the collector is sure to find on every excursion in the neighbourhood of Wisby, there is 

 one which at once strikes the sight by its peculiar shape, so much diverging from that of 

 the others. The thin and scanty epitheca, here and there as it were left in shreds and 

 the rest worn away, and especially the characteristic texture of the septa and the seleren- 

 chyraa of this coral, at once make it evident that it belongs to the Perforate Anthozoa. 

 I had designated it as a new genus and species, naming it Calostylis cribraria, in the 

 Öfversigt K. Vetenskaps-Akadem. Förhand!. 1868 p. 421 Pl. VI fig. 1 — 3. But I am 

 now aware of- its having been already some years ago named and figured by Prof. TH. 

 Kjerulf of Christiania, who in his »Veiviser ved Geologiske Excursioner i Christiania 

 Omegn» 1865 pages 22 & 25 denominates it Clisiophyllum denticulatum, original speci- 

 mens of which, kindly sent to me by Prof. Kjerulf, are, as I have fully convinced my- 

 self, in every particular identical with the Gotlandic specimens. It differs however widely 

 from the genus Clisiophyllum, being no Rugose coral at all, and must form a genus of its 

 own, as I have formerly stated and am pointing out in this paper. It may then most 

 properly be named 



CALOSTYLIS DENTICULATA. Kjerulf. 



• Plate, figs. 1 — 5. 

 Generally only single or independant polyparia are found, but this coral must 

 nevertheless be considered^ a compound one. Sometimes large specimens occur showing 

 rows of buds or gemmee bursting forth, all from the same side of the parent coral. Still 

 I never have been able to meet with large groups composed of such corallites in full 

 size. The general shape of the coral is a straight or very slightly bent cylindrical poly- 

 parium, very slowly increasing in width towards the superior or calicular end, so as to 

 continue almost of the same diameter for a great part of its length. The young indi- 

 viduals have attached themselves on other corals and shells, and their basis is expanded 

 into flat, broad epithecal excrescences. The epitheca is, as stated, only a very thin and 

 fragmentary coating, being evidently secreted only with interruptions, or, as it were, periodi- 

 cally, and disposed in detached zones without any continuity between them. Often the epi- 

 theca is completely wanting on well preserved specimens, that bear no indication what- 

 ever of having been worn or altered since their imbedding or previous to it. The exteriör 

 edges of the septa are in such specimens laid bare to the eye. This arrangement of the 



x ) The Anthozoa Rugosa of Gotland muster a strength of somewhat above fifty species in many varieties, 

 and the Anthozoa Tabulata are quite as many. 



