21ie Galena and Maquoketa Series. — Sardeson. 187 
species that crossed with K. inci'ebescens, or is luerel}^ con- 
fused because of its variations with the last named, I am not 
able to prove. The interior characters are unknown. li. 
minnesotensis, B. increhescens and R. latlcosf.afa appear to be 
all represented in the 'I'renton formation of New York and 
Kentucky. Bhynchonella capax Conrad succeeds li. increbes- 
cens but it is rare at first, and few specimens are known ex- 
cept in the upper Maquoketa. It is not evident however 
that the first are nearer to B. increbescens sensu stricto, 
in type than any others are, though both these species have 
elevated concentric, laminar growth lines. B. peHameJh>s<i 
Whitf., has not been re discovered, unless it is B. cnpax Con. 
B. anticostiensis Bill, has a straighter beak than B. increbes- 
cens Hall. B. neenah Whitf., is said to have a much deeper 
median sinus and a very prominent median plication. The 
three last named are from the top of the Maquoketa series. B. 
dentafa Hall which has a single plication in the median sinus, 
is from the equivalent horizon in Ohio., there associated with 
B. cap ax. 
Conclusion. 
Winchell and Schuchert* are of tiie opinion that there can 
be little advantage to the geologist or the biologist in giving 
names to the "'variations" of Plectambonites sericea., Orfliis 
testudinaria and others of like character, Whitfieldf and 
Meek;}; had expressed similar views, and all have considered 
the "varieties" as not distinct. I have endeavored to learn 
how far the same are distinct and distinguishable, and have 
become convinced that the different kinds are not united in 
the way Ihat had been believed, in most cases. At all events, 
these "species" with their many " variaties," are our most 
abundant Ordovician fossils, and to slight them is equivalent 
to rejecting the more complete and detailed geologic and pal- 
eontologic evidence in favor of poorer, more isolated, though 
conveniently distinct data. I have not hesitated to give the 
"varieties" specific designations, because they are important 
and worthy of recognition, but I do not mean to say thereb}'^ 
that it would not have been useless for authors to give names 
*Fiaal Rep. Geol. Sur. Minnesota, vol. iii. p. 415. 
tGeol. Wis., vol. iv. p. 258. 
jPal. Ohio, vol. i, p. 109. 
