1 86 NEW YORK STAIE MUSEUM 



PLATE 8 



iClionolithes (Vioa) priscus McCoy, cast of 

 borings in a shell of Pterinea demissa (Conrad) 

 McCoy [after McCoy, Brit. Paleoz. Foss. pi. iB, fig. i, la] 



2 The same. A series of clavate tubes in the shell substance 



of Leptocoelia flabellites (Conrad) all starting 

 from the margin of the valve at a definite period of growth 

 in the shell, x 2. Oriskany sandstone. Highland Mills, 

 N. Y. 



3 The same in a valve of Spirifer from the Chemung group 



near Sideling hill, Maryland, x 3 



4 The same. A valve of Aviculopecten from the Chemung 



group (Upper Devonic) of Allegany county, N. Y. with a 

 series of borings all beginning at a definite growth stage 

 of the shell beyond which shell growth has continued, 

 indicating that the mollusk was alive when the borings 

 were begun and continued to live while they were making 



5 A valve of Spirifer granulosus from the Hamilton 



shales of New York, with several such borings 



6 A tube cast in the valve of the brachiopod Leptostro- 



phia perplana (Conrad) . The sponge started to 

 bore at the thickened cardinal process of the dorsal valve 

 and on account of the thinness of the valve was com- 

 pelled to make its tube broader than high. At the inner 

 end the tube spreads out and shows a tendency to divide. 

 X 3. From the Hamilton shales of New York 



7 Another example of a flattened tube cast on a thin shelled 



pelecypod of the Hamilton group, N. Y. 



8 Clavate borings in a valve of Leptostrophia oris- 



k a n i a , Oriskany limestone, Becraft mountain, N. Y., 

 X3 



