234 Forty-third Report on the State Museum. 



There is one striking feature, however, that will separate the American 

 species from Irish specimens of 8. cus2ndata. The area of the ventral 

 valve in the first is rarely perfectly flat, it being in nearly all the 

 specimens I have seen, more or less arched. On the contrary, as is 

 shown in the four specimens of the second before me, the area is not 

 arched but reclines, and the beak in each is distinctly deflected to one 

 side. Tlie same peculiarities are also shown in Sowerby's flgures, * 

 and Prof. King says,t "in&tead of being incurved, as is usual 

 [among Palliobranchs], the umbone displays more tendency to the 

 opposite character, or to become tivisted, like that of Streptorhynchus." 

 The plicated portion of the ventral valve in American specimens is 

 always convex, while in the four Irish specimens already mentioned, 

 it is flat or slightly concave. These characters, if constant, certainly 

 should be regarded as of specific value. To determine this point it will 

 be necessary to examine a greater number of specimens than I have 

 been able to study. Under these circumstances I think it advisable 

 to retain Prof. Hall's name, S. carteri, as a distinct species from 

 the European S. cuspidaia, until some one shall prove the features 

 variable. 



Spirifer capax, Hall, from the Devonian of Iowa, has often been 

 referred to by authors as another probable synonym of this species. 

 Prof. Calvin | has shown that it is the internal cast of Spirifer 

 parryanus, Hall. I have seen a number of specimens, none of which 

 have the internal character of the genus Syringothyris. 



Distribution. — Lower Carboniferous as follows: In the Bedford 

 shale, at Bedford, Ohio ; Waverly sandstones of Licking county. 

 Ohio; Choteau group of Marion and Pike county, Missouri; Kinder- 

 hook and Burlington groups at Burlington, Iowa. Lower Carbonif- 

 erous strata of the White Pine Mountains; Kichmond Mi; Eureka 

 District, Nevada, and near Clendenin, Montana. 



Sybingothyris ANGULA.TA. Simpsou. 



Syringothyris angulata, Simpson, 1889. American Philosophical Society, 

 p. MO, figs. 1, 2, 3. 



This species is closely related to S. carteri, Hall. It holds th^ same 

 geological position as that species, and may prove to be identical with 

 it. Still it has a somewhat different expression in being smaller, with 

 the hinge extremities drawn out, and having the plications more 

 pronounced and sharper. 



Distribution. — Waverly group, near Warren, Pennsylvania. 



* Mineral Conchology table, 120. 



t Annals and Magazine Natural History, 4 ser., vol. 2, p. 2. 



t Bulletin Laboratories State University, Iowa, p. 19, 1888. 



