424 
BULLETIN OF THE NATURAL HISTORY SOCIETY. 
Fi«.. 5. 
Acrothele avia, niut. putpis, n. mut. 6 x 6.j x 1 mm. Mag. | 
— a Ventral valve, mould of interior ; — h Dorsal valve^ 
interior. From Assise E.3o? (Upper Etchemin.), Dugald 
Brook, Escasonie, N. S. See p. 398, 402. 
Fig. 6. 
Acrothele Mattheivi var. costata, 5x6 mm. Mag. 
From the Protolenus Beds, Hanford Brook, St. John Co., 
N. B. See p. 397. 
Fig. 7. 
Acrothejp avia — Enlarged sculpture. See Plate XVII. 
Plate XYII. 
Fig. 1. 
Acrothele avia 9 x 10 x 1 mm. Mag. ^ (except c. to /.); — a 
Ventral valve, central part ; — h Same seen from the side ; 
— c Ventral, interior of ; — d Dorsal valve ; — e Same in 
outline ; — f Dorsal, interior — c. to f. mag. f. Fig. 7 of 
Plate XVI ; — a Surface sculpture on lateral slope of ven- 
tral j — h Sculpture on middle part of ventral. Both mag. 
Y- All from Assise E.3e (Upper Etchemin.) at Dugald 
Brook, Escasonie, N. S. See p. 396, 402. 
Fig. 2. 
Acrothele avia, broad form, ventral, 7 x 9|^ x 1 mm. Mag. \, 
Dorsal 5^ x 7 mm., mag. — a Ventral valve; — h 
Dorsal valve, mould of interior. From Assise E.3(i (Up- 
per Etchemin.) at Dougald Brook, Escasonie, N. S. See p. 
397. 
Fig. 3. 
Acrothele proles 8^ x 9 x 1 mm. Mag. \ ; — a Ventral valve ; 
— h Interior of same ; — c A smaller dorsal valve ; — d In- 
terior 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. 400, 402. 
Fig. 4. 
Acrothele Matthewi mut. prima. Mag. | ; — a Ventral valve, 
showing the umbo close to the posterior margin ; — h Same 
in profile. From Protolenus Beds (C.16), Hanford Brook, 
N. B. See p. 397, 402. 
Fig. 5. 
Acrothf'le Matthewi. ]\Iag. f ; —a Dorsal valve, interior, show, 
ing 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. 397, 402. 
