WH1TEAVE8.] FOSSILS OF HAMILTON FORMATION OP ONTARIO. Ill 



MOLLUSCOIDEA. 

 BRACHIOPODA. 



LlNQULA LIQEA, Hall. 



Lingvla ligea, Hall. 1860. Thirteenth Rep. N. York St. Cab. Nat. Hist., p. 76. 

 " 1867. Pal. St. N. Yorlv, vol. IV., part 1, p. 7, pi. 1, figs. 2a, 

 and 2b. 



Near Thedford, Rev. Hector Currie, 1882 : one specimen. 



LiNQULA Thedfordensis. (N. Sp.) 

 Plate 15, fig. 1. 



Shell strongly compressed, thickest in the umbonal region : lateral 

 outline rather broadly subelliptical; length about one-third greater 

 than the maximum breadth. Lateral margins nearly straight and 

 but slightlj' convex in their central portions, but narrowing gently in 

 a convex curve at and towards each extremity ; anterior margin 

 regularly rounded ; cardinal slopes slightly convex, diverging forward 

 and outward from the beaks at an angle of about one hundred and 

 twelve degrees, and not at all angular or even subangular at their 

 junction with the lateral margins ; beaks small and not very prominent. 



Surface polished and glossy, but marked with tine, concentric, raised 

 lines of growth, which are crossed by numerous, closely arranged and 

 almost equally minute radiating raised lines, which extend from the 

 beaks to the anterior margin and are most prominent on and near the 

 latter. 



Dimensions of the specimen figured: maximum length, fifteen milli- 

 metres and a half; greatest breadth, eleven mm. ; maximum thickness, 

 two and a half In another specimen the dimensions are : length, 

 twenty-one mm. ; breadth (approximately) fourteen and a half; thick- 

 ness, three. 



Near Thedford, Eev. Hector Currie, 1882 : two specimens, the smal- 

 ler and more perfect of which is figured. In the other the beak is 

 somewhat more prominent and pointed. 



This species seems to be somewhat nearly related to the Lingula 

 maida of Hall, *but differs therefrom in its broader and more regularly 

 elliptical outline, as viewed laterally, as well as in the greater convexity 

 of its cardinal slopes, which diverge at a much more obtuse angle. It 



•Pal. State New York, vol. IV., pt. 1, p. 9, pi, 2, flg. 13. 



