The Relationship of the Tetracoralla to the Hexacoralla. 175 



Calostylis cribraria Lindstrom. Ofv. K. Svenska Vetensk.- 

 Akad. ForhandL, Vol. XXV, 1868:421. 



Calostylis denticulata Lindstrom. K. Svenska Vetensk.-Akad. 

 Handlingar, Vol. IX, No. 6, 1870: i. 



Locality and horizon: Near Visby, Gothland, Sweden. Silurian. 

 Calostylis lindstrbmi Nicholson and Etheridge. 



Mon. Sil. Foss. Girvan Dist., Vol. I, 1878: 65. 



Locality and horizon: Penkill, near Girvan, Ayrshire, Scot- 

 land. Silurian. 

 Calostylis {?) awof^r^om Nicholson and Lydekker. 



Man. Pal., Vol. I, 1889: 307, Fig. 189. 



Locality and horizon: Shropshire, England. Silurian (Wen- 

 lock). 



Remarks. — No description by the above authors has been 

 found. The figures in the Manual of Palceontology, however, 

 are adequate. Lindstrom believed that these forms belong 

 with the genus H elminthidium. 

 Calostylis spongiosa Foerste. 



Bull. Ky. Geol. Surv., No. 7, 1906: 322. 



Locality and horizon: Irvine, Kentucky. Silurian (Waco lime- 

 stone). 



Previous Position. — On account of its porous septa Calostylis 

 was at first placed among the Hexacoralla. This was opposed 

 by Neumayr, who made a strong argument based on the facts 

 of geological occurrence of coral groups. He pointed out the 

 absence of perforations in forms of Tetracoralla from Silurian 

 until Triassic time, and as there is no other evidence of Paleozoic 

 forms of this sub-class with perforated skeletons, he was led to 

 believe that this peculiar specialization occurred in the Tetra- 

 coralla, perhaps in response to a cause like that which has forced 

 so many of the corals since the Paleozoic to assume a similar 

 character. Other points of less force were made by both sides 

 in the controversy. Those who favored Lindstrom's view 

 pointed to the peculiar spongy columella, the manner of budding, 

 and the lack of a well defined epitheca, while those favoring the 

 other side directed attention to the external shape as being essen- 

 tially that of the Tetracoralla, and held that the budding 

 phenomena in this sub-class could lead to such a grouping as 

 that in Calostylis. 



