EXPLANATION OF PLATE LXXIV. 



TEREDO IRSEGULARIS Gabb, p. 656 



1-2. Anterior and lateral views of a shell in position in its tube 



of habitation. 



3. Mass of fossil wood with included tubes. The original of 

 figures i and 2 was removed from this. 



Merchantville clay-marl; Lenola, (/6j). 



TURNUS KUMMELI n. sp.. p. 6$2 



4-5. Lateral views of two left valves. 



6. The same as figure 5, (x2). 



Marshalltown clay-marl; near Swedesboro, (177). 



PHOLAS CITHARA Morton, p. 651 



7. Lateral view of an internal cast. 



Woodbury clay; Lorillard, (102). 



MARTESIA CRETACEA Gabb, p. 654 



8-9. Lateral and ventral views of an internal cast, (x2)^ 

 lo-ii. Lateral and cardinal views of an internal cast, (x2). 



Marshalltown clay-marl; near Sivedesboro, (/77). 



POLORTHUS TIBIALIS (Morton) , p. 659 



12. View of a group of the tube casts, showing their usual form. 



Nearly all have their lower ends broken off. 



13. Enlarged view of the upper end of a tube showing the partial 



septa of this part of the tube. 



14. Enlarged view of the aperture. 



15. Enlargement of the upper end of a cast, showing the 



muscular scar. (All figures after Whitfield.) 

 Vincentown lime sand. 



1032 



