EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 1 95 



in which these seem to pass the definition of L. oriskania save 

 perhaps in the matter of size in which they at times surpass the New York 

 shell, and in the tendency to thicken and obscure the rugations or render 

 them irregular. The extreme of this tendency is represented by a single 

 specimen here figured in which the surface has become rough and squamous. 

 There is a manifest individual difference in the character of the concentric 

 wrinkles ; if these are developed with force and regularity at an early stage 

 they maintain this character to near full growth but if the rugae are not 

 regular or distinct in early growth they become obsolete early. 



Dimensions. An average typically developed individual measures, 

 width on hinge, 20 mm ; length 14 mm. An old and thickened example is 

 27 mm long and 38 mm on the hinge. 



Localities. Little Gaspe ; Grande Greve, abundant along the shore 

 outcrops at Fruing's and Lehuquet's ; also at Indian Cove. 



Leptostrophia tardifi nov. 



Plate 39^ figures 1-4 



Shell of uniformly medium size, averaging about that of the L. per- 

 plana; flat or broadly convex in the umbonal region, hinge line straight 

 and not extended, commissural margin subcircular. Surface radii numerous, 

 composed of rounded lines with very narrow interspaces, the former in- 

 creasing quite irregularly by bifurcation but keeping a subequal appearance 

 throughout. The surface seems to have been early subject to irregular 

 growth from injury or pathologic condition of the mantle, rapid duplication 

 of the striae following each of these cicatrices. These striae are covered 

 by extremely fine concentric lines. Attention is directed to the differing 

 expressions of the surface markings on these allied species, L. tu 1 1 i a, L. 

 magnifica, L. irene and L. tardifi. 



Dimensions of an average specimen 35 mm in width on the hinge, length 

 25 mm. 



Locality. Perce Rock. 



Species name : Richardson Tardif esq., of Perce. 



Strophonella (Amphistrophia) continens nov. 



Plate 40, figures i-ii 



Strophomena p u n c t u 1 i f er a Conrad, variety, Billings. Palaeozoic Fossils. 

 1874. V. 2, pt I, p. 32 



IVIr Billings after describing shells from division i of the Gaspe series 

 (St Alban limestone) which he identified with S. punctulifera of the 

 Helderbergian of New York, specifies a variety of the species in regard to 

 which he briefly remarks : 



The specimens to which the above description relates, occur in Div. i of the Gasp6 

 limestone. In the upper part of the series a variety occurs with fine threadlike radii, 



