50 PALJEONTOLOGY OF NEW YORK. 



the shell than in others, a variation which may be due to the easy destruction 

 of the delicate pores which are exceedingly small and much .finer than in 

 Spiriperina, Cyrtina, and the terebratuloids. 



Attention, however, may be directed to an interesting species from the Cho- 

 teau limestone of Cooper county, Missouri, small in size, cyrtiniform in figure, 

 with a highly and coarsely punctate shell.* 



While regarding Svringothyris as an outcome from Spirifer along the line of 

 the Ostiolati, the genus contains an occasional species which is isomorphic with 

 the Aperturati. Such, for example, are the S. Randalli, Simpson, from the 

 Waverly faunas of eastern Pennsylvania, and the S. distans, McCoy, of the Coal 

 Measures of Great Britain and Belgium. 



The type species of Syringothvris was named by Professor Winchell, 

 Syringothyris typa, and was derived from the Burlington limestone. Drs. King 

 and Davidson both regarded this fossil identical with Spirifer cuspidatus, Martin, 

 and they have been followed by Meek, Walcott and Herrick, but Schochert f 

 has pointed out differences which may serve to keep the European and Amer- 

 ican forms distinct. 



The fact that the species Spirifer Carteri, Hall, from the Waverly sandstones 

 of Ohio, is a Syringothyris has been long known. Swallow's Spirifer {Cyrlia ?) 

 Hannibalensis, from the Choteau limestone, is a smaller form of the same specific 

 type as S. typa. 



In the Waverly fauna of Pennsylvania occur the species described by Mr. G. 

 B. Simpson as S. Randalli and S. angulata.X In the development of the same 

 fauna in Ohio, and in the Keokuk group of Indiana, Illinois and Iowa, S. texta. 

 Hall, and its allies are not uncommon species {Spirifer texttis, Hall, S. subcuspi- 

 datus. Hall, S. propinquus. Hall). 



*Thia is evidently an undescribed shell, and as it is an impoi-tant one for our purposes the name 

 SyrinffothyrU MUtouri is proposed. Its highly punctate shell, its size and form, all indicate a deviation 

 toward Cybtika, while the canalifoi-m transvei'se plate is developed as a very delicate structure. For a 

 fuller description of the sjiecies see the supplement to this volume. 



t On Syringothyris, Winchell, and its American species ; RepoH of the N. Y. State Geologist for 1889, 

 p. 380. 1890. 



J Proc. American Philoso])hical Society, vol. xvi, 1889, p. 435. These were described as 8. Randalli 

 and var angulata, but as the formei' possesses a plicate fold and sinus and in the latter the fold and sinus 

 ■re amootb, it will be better to regard them as distinct species. 



