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1. DESCRIPTIONS OF NEW SPECIES OF BRACIIIOPODA, 



TROM THE UPPER HELDERBERG, HAMILTON AND CHEMUNG GROUPS. 



GENUS LINGULA ( Bruguiere). 



" LINGULA CERYX { n. s.)." 

 A single specimen has been obtained, three-fourths of an inch 

 in length by half an inch in breadth. Very little of the shell is 

 preserved ; merely sufficient to show that it was marked by fine 

 concentric striae, with the cardinal margin thickened. The cast 

 has a distinct oval impression a little above the centre, showing 

 the mark of a muscular callosity at that point. 



This species resembles in form the L. densa of the Hamilton group, but 

 has not the strong radiating striae of that species, while the subcentral 

 muscular callosity is also different. 



Except that this is the only representative of the genus known to me in 

 the Schoharie grit, I would not have thought it worth while to designate 

 the species from a single imperfect specimen. 



Geological formation and locality. In the Schoharie grit : near Clarks- 

 ville, Albany county. 



" LINGULA DESIDERATA (n.s.)." 

 Shell robust, elliptical, convex, the width equal to about four- 

 sevenths of the length, the greatest width being above the" 

 middle of the shell. 

 Surface marked by fine and closely arranged concentric strise ; 

 the interior of the shell, and the cast, showing strong radiating 

 striaB. Length a little less than half an inch. 



The specimen is apparently a dorsal valve, which is truncate, and perhaps 

 a little imperfect at the beak. In its general form it resembles L. ligea^ 

 but is wider above the centre and more convex, while it is larger than any 

 specimens of that species in the collection. The presence of radiating striae 

 has not been observed in L. ligea. Other specimens are required for a 

 satisfactory determination of its character. 



Geological formation and locality. In the Corniferous limestone of the 

 Upper Helderberg group, at Lapham's mill, Ontario county. 



