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PROCEEDINGS OF THE ROCHESTER ACADEMY OF SCIENCE 



Vol. 4., pp. 203-210. FEBRUARY 12, 1906. 



LIBRARY 

 NEW VORK 



ARTHROPHYCUS AND D^DALUS OF BURROW ORIGIN* botanical 

 By Clifton J, Sarle. 



The conclusion reached by the writer regarding the nature of the 

 problematic genera Arthrophycus Hall and Daedalus (Rouault) is 

 the result of a study of Arthrophycus alleghaniensis (Harlan) \A. 

 harlani (Conrad), Harlayiia halli Goeppert] and D<zdalus archimcdes 

 (Ringueberg), as they occur in the outcrop of the Medina (basal 

 Silurian), in the Genesee gorge at Rochester, N. Y. 



A. alleghaniensis is known as simple or branching vermiform 

 ridges having numerous transverse corrugations and a median longi- 

 tudinal depression. The form here called D. archimedes occurs as 

 rugose plates which may be flat, vertical, and roughly U- or tongue- 

 shaped in outline, or crimped into irregular shapes, or may form 

 inverted archimedean spirals. One of the spirals was described by 

 Dr. Ringueberg as Spirophyton archimedes . In Europe the genus is 

 known as Vexillimi, but finding this name preoccupied, I have 

 adopted the name Dtzdahis^ which was used by Rouault, the founder 

 of the genus Vexilhwi, for some forms which he at first regarded 

 as generically distinct from it. 



Arthrophyc2is has been considered as the cast of a seaweed, a 

 worm, the trail of various animals, branched passages, and as the 

 result of purely mechanical forces. Its appearance has even suggested 

 the arms of an ophiuroid. Dadalus has been considered as a sea- 

 weed, a sponge, and as the result of mechanical forces, for example, 

 eddying water and rills. 



The writer finds that Arthrophycus has a structure very similar to 

 that of Dcedahis, and has concluded that both are the result of the 

 burrowing of animals. 



♦This is an abstract of a paper forming part of a thesis accepted bv the faculty of Yale 

 Graduate School for the degree of Doctor of Philosophy. It was read before Section E of the 

 American Association for the Advancement of Science, at Syracuse, July 21, 1905. The pub- 

 lished paper will be fully illustrated. 



20, Proc. Roch. Acad. Science, \'ol. 4, Feb. 12, 1906. 



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