7IO E. M. KINDLE 



occur in great numbers, but not so abundant, also in the Middle 

 Eden. In Kentucky they are common also locally in the Mount 

 Hope bed, at the base of the Maysville. They occur often near the 

 middle of the Arnheim and at various intervals in the Lower and 

 Middle Richmond in the three states mentioned." Dr. Foerste 

 has recorded^ a considerable number of observations on the lime- 

 stone ripple-marks in the Ordovician and Silurian formations 

 of these three states. Most of those which he observed appear 

 to be of large size, those seen at one locality having crests 49 inches 

 apart which rise 3I inches above the troughs.^ Foerste remarks 

 that "their unusual size will, however, attract attention even from 

 one familiar with the work of the sea." Moore and Allen^ have 

 pubhshed photographs and descriptions of Upper Ordovician 

 (Richmond) limestone ripple-marks with an average amplitude 

 of 2.63 feet which occur in eastern Indiana. 



In New York state, Miller'' has described ripple-marks in the 

 Trenton limestone of Lewis county which measure 24-56 inches 

 from crest to crest with troughs 4-7 inches deep. At another 

 locality in the same state, Professor Gushing^ has described ripple- 

 marks in the Trenton limestone with an amplitude of 9-15 inches 

 and a depth of 1-3 inches. Gushing remarks concerning these 

 that "they are considerably broader than the usual ripple-marks 

 in sandstones." This observation, it may be noted, tends to con- 

 firm the opinion already expressed by me that sandstone ripple- 

 marks have generally a comparatively small amplitude. 



But few references to ripple-marks on Silurian limestones have 

 come under my notice. Two of these which relate to New York 

 and Ohio localities may be cited. East of Lockport, New York, 

 Kindle and Taylor* report ripple-marks in the uppermost member 



^ "On Clinton Conglomerates and Wave-Marks in Ohio and Kentucky," Jour. 

 Geol. Ill (1895); i-io (reprint). "The Richmond Group along the Western Side 

 of the Cincinnati Anticline in Indiana and Kentucky," Am. Geol., XXXI (1903), 

 333-61. 



^ Jour. Geol., Ill, 37. 



i Proc. Ind. Acad. Sci. igoi (1902), pp. 216-18, Pis. 1-3. 



4 Bull. N.Y. State Mus. No. 135 (1910), p. 36. 



5 Bull. N.Y. Stale Mus. Nat. Hist. No. 77 (1905), p. 34. 

 ('Folio U.S.G.S. No. igo (1913), p. 7. 



