EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA I 57 



broader and much less incurved, which present quite regularly alternating 

 radial ribs crossed by elevated concentric lines. These we propose to 

 identify with P t. proteus recognizing a distinctive difference by the 

 employment of the term mutation. These shells are not common. 

 Locality. Fruing's, Grande Greve. 



Megambonia denysia nov. 



Plate 2T, figures 8-ia 



Shell very small, suborbicular in outline and rotund in contour. Auricle 

 not prominent, byssal groove broad, shallow and indistinct, but visible nearly 

 to the beak. Surface very finely radiate on the body of the shell but with 

 fewer radii on the auricle. The orbicular outline, regular convexity and 

 feeble byssal groove seem to indicate this as distinct from the foregoing, 

 though not varying materially in surface characters. Further knowledge of 

 the shell may determine a closer relationship in the two. 



Dimensions. Hight and width, 7 mm. 



Locality. Perce Rock. 



Species name. Joseph Denys, Recollet missioner at Perce, 1685. 



Megambonia crenistriata Clarke 



Plate 21, figures 6, 7 



Megambonia crenistriata Clarke. N. Y. State Mus. Mem. 3. 1900. p. 53, 

 pi. 4, fig. 15-17 



This species differs from M. bellistriata of the arenaceous New 

 York Oriskany (Albany and Schoharie counties) in its large auricle with 

 deep sulcus reaching to the beak, the surface of this part being almost free 

 of radial lines. Such evidences as there are of the latter only nick the 

 edges of the lamellose concentric growth lines into a series of obscure scol- 

 lops ; no trace of them is seen either on sculpture or internal casts. 

 Megambonia bellistriata has decided radial lines on the auricle 

 and a very shallow byssal groove. 



The Gaspe limestone specimens have the surface finely radiate over 

 the body of the shell as in the New York specimens. 



Locality. Rare at Grande Greve. 



Cypricardinia distincta Billings 



Plate 24, figures 12-19 



Cypricardinia distincta Billings. Palaeozoic Fossils. 1874. v. 2, pt i, 

 p. 56, fig. 26, 27 



Under this name the author cited and illustrated the two extremes of 

 variation in this species, one elongate with broad and few growth bands and 



