1905.] NATURAL SCIENCES OF PHILADELPHIA. 361 



Plate XXXI, fig. 9. — Fulgur canaliculatum Say. Recent. Atlantic City, N. J. 

 Length = 170 mm. Normal adult individual. 



Fig. 10. — Fulgur canaliculatum Say. Recent. Longport, N. J. Length 

 = 168 mm. Adult individual which has been injured early in life 

 and exhibits extra-specific adventitious senility. 



Fig. 11. — Fulgur pyrum DiUw. Recent. Cards Sound, Dade County, Fla. 

 Length =81 mm. Normal adult individual. Introduced for com- 

 parison with fig. 10. 



Fig. 12. — Fulgur maximum Qon. Miocene. Yorktown, Va. Length = 165 

 mm. Adult individual exhibiting extreme senility — very heavy 

 thick shell, irregular growth lines, discontinuous ornamentation and 

 a large swelling on the anterior or branchial siphon. 



