p. E. Raymond — History of Corals, etc. 343 



Art. XXVIII. — The History of Corals and the ^^ Lime- 

 less'' Oceans; by Percy E. Raymond. 



One swallow may not make a summer, but in the realms 

 of Paleontology one discovery may let a flood of light into 

 provinces previously most obscure. Perhaps the most 

 remarkable single ^'find'^ which ever rewarded the fossil 

 hunter was that made by Dr. Walcott at Burgess Pass, 

 British Columbia. No such aggregation of soft-bodied 

 animals had ever been seen in the rocks before, not even 

 at Solenhofen. The fossils are so unusual, and so differ- 

 ent in their preservation from those usually studied, that 

 even now, ten years after the first of them was described, 

 their significance is not fully appreciated. 



Among these fossils there is one which has given rise to 

 certain suggestions which I wish to bring forward, as to 

 a possible interpretation of the somewhat obscure history 

 of the corals. 



Mackensia costalis "Walcott^ (fig. 3) was described as a 

 holothurian, but H. L. Clark^ in a review of the original 

 paper, and after a study of the specimens, considered it 

 an Actinian, in which determination Austin H. Clark has 

 concurred.^ An extract from the article by the latter 

 may be quoted : 



''The type specimen of Mackenzia costalis shows a pleated 

 structure which can only be interpreted as due to longitudinal 

 mesenteries, probably eight in number ; there appear to have been 

 sixteen processes around the mouth, which probably indicate six- 

 teen tentacles retracted before preservation ; the distal portion of 

 the body resembles closely the distal portion of the body in the 

 genus Edwardsia. Thus, as Mackenzia costalis presents charac- 

 ters not found outside of the Zoantharia, and in that group 

 peculiar to the family Edwardsiidae, it seems necessary to assign 

 it to a position in the family Edwardsiidae, near the genus 

 Edwardsia." (loc. cit. p. 507.) 



This determination of the fossil is of peculiar interest, 

 since the Edwardsiidae are considered the most primitive 

 of the Zoantharia, and in their ontogeny, modern Hexa- 

 ■^oralla pass through an Edwardsia stage. There is, fur- 



^ Smithson. MiscL Colls., vol. 57, p. 55, pi. 13, figs. 2, 3, 1911. 

 ' Science, vol. 35, p. 275, Feb. 16, 1912. 

 ' Am. Naturalist, vol. 47, p. 503, 1913. 



