PLATE V. 



FIG. 1. Acrothtlc (ivia 9 x 10 x 1 mm. Mag. f- (except c. to/.) ; Ventral valve, cen- 

 tral part ; I Same seen from the side ; c Ventral, interior of ; d Dorsal 

 valve; c Same in outline; / Dorsal, interior c. to/, mag. f-. Fig. 7 of 

 Plate IV ; a Surface sculpture on lateral slope of ventral; b Sculpture 

 on middle part of ventral. Both mag. Y- All from Assise E. 3e (Upper Etche- 

 min) at Dugald brook, Escasonie, N. S. See p. !)8. 



FIG. 2. Acrothele aria, broad form, ventral, 7 x OA x 1 mm. Mag. ^, Dorsal 5^ x 7 mm., 

 mag. f ; a Ventral valve ; 6 Dorsal valve, mould of interior. From Assise 

 E. 3d (Upper Etchemin) at Dugald brook, Escasonie, N. S. See p. 99. 



FIG. 3. Acrothele proles 8i x 9 x 1 mm. Mag. ; a Ventral valve ; b Interior of same ; 

 c A smaller dorsal valve; d Interior of same; e Outline of the valves 

 from the side. From Assise E. 3/ (Upper Etchemin.) at Gillis', Indian brook, 

 Escasonie, N. S. See p. 102. 



FIG. 4. Acrothele Matthcwi, Hartt, mut. prima. Mag. f ;-a Ventral valve, showing the 

 umbo close to the posterior margin ; b Same in profile. From Protolenus 

 Beds (C. \b), Hanford brook, N. B. See p. 104. 



FIG. 5. Acrothele Matthewi. Mag. f ; a Dorsal valve, interior, showing median septem 

 and its branches, and fine striae on the valve radiating to the anterior and 

 lateral margins ; b This valve in profile. From Lower Paradoxides Beds (C. 

 Ic), Hanford brook, N. B. See p. 104. 



FIG. 6. Acrothele AFattcwi mut. lata. Mag. ; a Ventral valve, interior ; has two pits 

 in front of the foramen, diverging arched ridges on each side of the foramen, 

 and a low ridge on each side of the foramen extending to the hinge line ; 6 

 A dorsal in profile, showing the position of the hinge line. From Protolenus 

 Beds (C. 1 b), Hanford brook, N. B. See p. 104. 



