112 NEW YORK STATE MUSEUM 



Orthothetes (Schuchertella) woolworthanus Hall (sp.) 



Plate 41^ figure 14 



Strophomena w o o 1 w o r t h a n a Hall. Palaeontology of New York. 1859. 

 3 : 192, pl. 17, fig- I. 2 



A characteristic species of the Helderbergian (New Scotland beds). 

 Cape Rosier Cove, lower division. 



Orthostrophia canadensis nov. 



Plate 43, figures 5, 6 



This singular genus which has been recognized only at the horizon of 

 the Helderbergian fauna is represented by two described species, O. s t r o- 

 phomenoides Hall (New York) and O. halli Safford (Perry county, 

 Tenn.) That before us is smaller than these, the valves well characterized 

 by the muscle scars peculiar to the genus. Their features in detail are as 

 follows : The valves are subcircular with a straight hinge ; in contour the 

 ventral valve is the shallower but bears a high median ridge, while the 

 deeoer dorsal valve carries a broad and low median sinus. Inside, the ven- 

 tral valve has the muscular area concentrated posteriorly into a single scar 

 not more extensive than the single pedicle scar in more typical orthids ; the 

 dorsal valve has a thin erect cardinal process and four distinct adductor 

 scars. 



The surface is marked by radial striae of unequal size. 



Localities. We have a ventral valve of this species from the Grande 

 Cavee, and a dorsal valve from Cape Rosier Cove. This species is also 

 known to occur in the Square Lake limestone of northern Maine. 



Dalmanella subcarinata Hall 



Orthis subcarinata Hall. Palaeontology of New York. 1859. 3:169, pl. 12, 

 fig. 7-21 



This species, very common in the New Scotland beds of Albany and 

 Schoharie counties, is represented by thoroughly characteristic and typical 

 specimens. 



Locality. Cape Rosier Cove, lower beds. 



Dalmanella cf. discus Hall 



See Orthis discus Hall. Palaeontology of New York. 1859. 3 : 165, pl. loa, 

 fig. 7-12 



A series of small subcircular and subconvex valves appears to agree 

 with the typical expression of this species from the New Scotland beds. 

 Locality. Cape Rosier Cove, upper beds. 



