PLATE IV. 



FIG. 1. Acrotreta Baileyi, 3 x 4 x 1 mm. Mag. f ; a Ventral, mould of interior; 

 I Same from the side ; c Dorsal, mould of interior ; d Same from the side. 

 (C.lrf) Lower Paradoxides Beds, Kings Co., N. B. See p. 97. 



FIG. 2. Acrotreta bisccta 3x3^ x 3 mm. Mag. f ; a Ventral valve ; b Mould of 

 interior from the side ; c Same seen from above ; d Dorsal valve ; c Mould 

 of interior from behind ; / Same from the side; g Same from above. From 

 the Dictyonema Beds, (C.Sc) McLeod brook, Boisdale, N. S. See p. 186. 



FIG. 3. Acrothelc abavia, 6^ x 6^ x mm. Mag, f ; a Ventral valve, interior, 

 the umbo is filled with a plug of fine sand ; b Same from the side ; c Doral 

 valve, interior, the shell is broken away at the umbo ; d Same from the side. 

 From Assise E.3a (Upper Etchemin.) at Dugald Brook, Escasonie, N. S. See 

 p. 100. 



FIG. 4. Acrothelc abavia, 5 x 6 x 1 mm. Mag. f ; a Ventral valve, interior ; 

 b Dorsal valve, interior. From Assise E.36 (Upper Etchemin.) at Dugald 

 brook, Escasonie, N. S. See p. 100. 



FIG. 5. Acrothele avia, mut. puteis, 6 x Gi x 1 mm. Mag. ^ ; * Ventral valve, 

 mould of interior ; b Dorsal valve, interior. From Assise E. 3d (Upper 

 Etchemin), Dugald brook, Escasonie, N. S. See p. 100. 



FIG. 6. Acrothele Matthewi var. costata, 5x6 mm. Mag. f . From the Protolenus Beds 

 (C. 16), Hanford brook, St. John Co., N. B. See p. 104. 



Flu. 7. Acrothele avia Enlarged sculpture. See Plate V. 



