194 NEW YORK STATE MUSEUM 



PLATE 12 



1 Clionolithes palmatus. A valve of the pelecypod 



Loxopteria dispar Sandberger, from the Portage 

 beds (Upper Devonic) of Correll's point, N. Y. in the 

 substance of which this cluster of frond-shaped cavities 

 lies. X 2 



2 The same. A somewhat more diffuse cluster in the shell 



substance of Loxonema danai Clarke from the 

 same formation and locality, x 5 



3 C a u 1 o s t r e p s i s taeniola. Stropheodonta 



cf . g i g a s McCoy from the Seigener schichten (Coblent- 

 zian) of Seifen. The margin of the brachiopod has been 

 entered on all sides simultaneously by these borers form- 

 ing loop-shaped tubes which are joined by a thin median 

 cavity. Together with these are simple tube casts of 

 Clionolithes priscus. I owe this specimen to 

 the kindness of Prof. E. Kayser. 



4 The same on Stropheodonta protaeniolata 



Maurer, same locality [after Maurer] 

 5, 6, 7 Large circular perforations in the valves of brachiopods, 

 probably made by the radula of predatory gastropods. 

 In figure 5 the brachiopod is Spirifer medialis 

 Hall from the Hamilton shales of New York; figure 6, 

 Meristella from the Oriskany limestone of Glenerie, N. Y. ; 

 and figure 7 a small Spirifer granulosus Conrad 

 from the Hamilton rocks. In 5 and 7 the hole is on the 

 dorsal valve and has precisely the same position with 

 reference to the shell and the animal within which the 

 gastropod was doubtless seeking. The hole, figure 6, has 

 the same position on the ventral valve of Meristella. It 

 is interesting to observe that the Spirifer in figure 5 and 

 the Meristella in figure 6 succeeded in forestalling the 

 purposes of the enemy by secreting a false floor beneath 

 the hole after it had perforated the shell. Spirifer, figure 

 7 may have fallen a victim to the attack as the hole is 

 not sealed. These are instructive illustrations of the early 

 acquisition of this perforating mode of attack by the 

 gastropods. 



I 



