236 Forty-third Report on the State Museum. 



la Beche. I am now convinced that it can not be the 8. cuspidatus; it 

 must belong to the genus Gyrtia, Dalman, having the deltidium and 

 area characterizing that genus. This deltidium, from its base at the 

 hinge to its apex at the beak, is about two inches. The area or hinge 

 is upwards of four inches in length. It is longitudinally ribbed, and 

 resembles somewhat in figure the Calceola heteroclyta, Defrance. I 

 believe it is the largest known of that genus." 



Found in the " Encrinital stratum near the Harpeth river, Davidson 

 county, Tennessee." 



Syringothykis texta. Hall's sp. 



Spirifer textus, Hall, 1857. Tenth; Eep. N. Y. State Cab. Nat. Hist., p. 169. 



Spirifer snbcuspidatus, Hall, 1858 (non Schnut, 1831). Geol. Surv., Iowa, 

 part 2, p. 646, pi. 20, fig. 5. 



Spirifer suhcuspidatus. Hall, 1867. Pal., N. Y., vol. 4, p. 249. 



Spirifer propinquus, Hall, 1858. Geol. Surv., Iowa, part 2, p. 647. 



Spirifer propinqnus, Meek and Worthen, 1868. Geol. Surv., 111., vol. 3, 

 p. 530, pi. 19, fig. 8. 



Spirifercnspidatiformis, S. A. Miller, 1889. North Am. Geol. Pal., p. 372. 



The original specimens from which the description was drawn up 

 in 1857, came from the Knobstone group of Indiana and have never 

 been figured. This species is usually met with in collections labeled 

 S. typa, which I have shown to be a synonym for S. carteri, Hall. It 

 differs from that species in never having the area of the ventral valve 

 so high, it being almost constantly one inch in height. The length 

 of the hinge-line in S. typa may be twice as great as the length of 

 valves (the most abundant form), or may be equal to it (rather 

 uncommon), while in S. carteri the hinge-line is constantly one-half 

 again as long as the length of valves. The sinus is also deeper and 

 often strongly produced into a wave-like extension or tongue, while 

 the fold is more elevated than in ^S*. carteri. The plications are also 

 more pronounced. Upon the whole, S. texta is a larger and more 

 robust species. 



Meek figured this species in 1875, and identified it with S. carteri. 

 Hall. His figures show clearly that he had 8. texta before him, these 

 being longer on the hinge-line, with the area comparatively shorter and 

 with a greater number of plications on each side of the fold and sinus 

 than is known in S. carteri from its various localities. I have collected 

 specimens at Sciotoville, Ohio, the source of his illustrated material, 

 and find them to agree with 8. texta in all characters except one. 

 They have from five to seven plications more on each side of the fold 

 and sinus than I have observed on specimens of this species as found 

 at the original locality in Indiana. 



