EARLY DEVOXIC IIISTORV OK NEW YORK AND EASTERN NORTH AMERICA I 85 



suspect that pedicle valves of the species have been brought together under 

 some other name. We may however here note the following circumstances : 

 With one exception all these specimens are from a single locality, the King's 

 road at Bartlett's, Grande Greve, in the middle beds of the series. The 

 only strophedontid associated with them here are ventral valves having 

 the characters of S. magni venter and to which Mr Billings applied this 

 name. It is to be noted that when Professor Hall described this latter 

 species he was not certain that the dorsal valves ascribed to it certainly 

 appertained thereto, W^e have however no such evidence as would justify 

 us in assuming the specific identity of these valves. 



Our specimens of S. lincklaeni all bear the characteristic smooth 

 exterior marked by broad concentric festoons with finer lines grouped 

 between them. In the Grande Greve specimens fine and very faint radial 

 lines are visible specially in the umbonal region. These are of subequal 

 size at the start, but at the margins of the shell they may be seen to be 

 arrancjed in fascicles. On the interior of the dorsal valve the radial striation 

 is much more pronounced and the radii are strongly pustulose. Specimens 

 from Perce have those features quite pronounced. 



Dimensions. An average specimen measures 55 mm on the hinge and 

 40 mm in length ; thus according with the specimens of the New York 

 Oriskany. 



Localities. In the upper horizon of no. 8, Grande Greve and on 

 Lehuquet's beach ; also at Perce Rock. 



Stropheodonta hunti nov. 



Plate 34, figures 4-12 



Shell small, regularly convexo-concave. Ventral valve most convex 

 along the median line, where the curvature is evenly arched and well ele- 

 vated ; lateral slopes depressed, at times slightly concave. Hinge line long, 

 straight, often with cardinal extensions ; the length of hinge is to the length 

 of shell as 3 to 2. The surface of the valve is uniformly smooth, usually 

 appearing nacreous and without lineation but well preserved exteriors show 

 an extremely fine radial striation hardly visible to the naked eye. About the 

 umbo are a few low corrugations, three or four in number and these become 

 extinct over the body of the valve. The dorsal valve shows the same degree 

 of corrugation as the ventral and cardinal area of conjoined valves indicates 

 nearly complete closure of the delthyrium and a fine denticulation extending 

 almost to the cardinal angles. The species has been observed frequently. 



The shell suggests both in size and in the aspect of its nacreous surface 

 the well known S. nacre a' from the Hamilton of New York for which 



' According to Schuchert this is the same shell as that described by Owen as C h o- 

 notes? i o \v e n s i s from the Middle Devonic of Iowa and if the latter is the older species 

 name it should take precedence. 



