116 EARLY ADAPTATION IN STAR-FISHES. 



They were not in any way bound to it. These Cyclonemas hung around the anal 

 orifice of the crinoids, nesting inside the arms of the creature and catching the 

 waste for their own nourishment. In the Devonian we find here and there one 

 of these coiled limpet-like shells attached to the crinoid in such a way as to cover 

 the proct so that nothing escaped. At this time the habit was not general. 

 In the early Carboniferous faunas this truly parasitic and dependent habit had 

 become almost universal. Then the crinoids reached their maximum of numerical 

 development and the snails, also at their maximum, began to surrender their 

 independent life at a very young stage, passing almost their entire existence 

 closely addicted to this easy life at another's cost. 



This dependent habit came to end we believe with the great faunal and 

 physical changes following paleozoic time. I think we are entitled to say that 

 through altered physical conditions or freer distribution of food, nature here did 

 rebound and this habit, degenerating and truly parasitic, was remedied without 

 aid of the clergy. At all events, there is no evidence whatever of such mutual 

 expressions between the crinoids and the great group of holostomatous snails 

 represented by the Capulidce, in the long periods of the Mesozoic and Tertiary. 

 The present fauna does show certain affiliations, some of them clearly dependent, 

 between living crinoids and some very degenerate snails, but as here different 

 groups of gastropods are involved there seems no evident connection between the 

 present and the ancient habit. 



I have given a detailed account of these early symbiotic associations in a 

 paper entitled " Beginnings of Dependent Life" 1 and in the presidential address 

 before the Paleontological Society. 2 



An interest of a similar order pertains to the discovery which this occasion 

 affords opportunity to describe. Recently we have uncovered in the Middle 

 Devonian rocks of Hamilton age on the west side of the Hudson river in the 

 town of Saugerties, N. Y., a layer of sandstone whose surface over the entire 

 area which could be laid bare was dotted with starfish. The surface exposed was 

 considerable, about 200 square feet, and from it were taken not less than 400 

 examples of the ancient starfish Palceaster eucharis, a species known before by 

 only an occasional example. The uncovered rock was slightly tilted, as it lies 

 in the region of Appalachian folding, and at both sides its continuity was de- 

 stroyed by crush zones of faulting. So we have no expression for the enormous 

 number of starfish that its original extent must have carried, but we may say 

 that never before have the rocks afforded such a vast array of starfish in so 

 limited a field. The Devonian shales at Bundenbach in the Rhineland produce 

 these creatures, many and various, but not in such overwhelming numbers. 

 One might stare at an oyster plantation on our northeast coast at low tide or 

 turn his gaze upward at the Milky Way and find a comparable abundance of 

 stars. Any other comparison fails. 



Museum 



1 Science, February 24, 1911. 



4th Rep. Director, 1908, pp. 147-169, pi. 1-13 



