16 Internal cast of ventral valve bearing tube fillings of a perforating 



sponge, Clionolithes priscus (McCoy) 

 Locality. Stony brook, Moose river 



Leptaena rhomboidalis (Wilckens) var ventricosa Hall 



Page 87 



17 A large and characteristic internal ventral cast 

 Locality. Stony brook, Moose river 



Hederella sp. 



18 A dorsal valve of Leptostrophia oriskania with an attached 



colony of this genus 



19 A portion of the colony enlarged 



Locality. Seven miles north of Kineo, Moosehead lake 



209 



