310 HuMPHREYS: THE NAME BUTHOTREPHIS GRACILIS 
gracilis Hall. This is especially true in the case of local lists of 
fossils, as for instance in such a list from the Trenton limestone 
of any locality, in which the name may be found included, without 
comment or adequate description, and the intention of the author 
of the list can only be inferred. The probability, of course, is 
that he is referring to the Trenton limestone species, but on the 
other hand he may be announcing the discovery of the Clinton B. 
gracilis in the Trenton limestone. Hence it is frequently more or 
less hazardous to draw conclusions in regard to the areal or 
stratigraphic distribution of the species recognized as Buthotrephis 
gracilis from such lists or other similar publications. 
In this connection, as an indication of the extent to which the 
application of correct nomenclature has been disregarded, the 
following data may be of interest: 
In sixty-five references to Buthotrephis gracilis Hall, twenty- 
three were found to refer more or less clearly to the Trenton 
species and twenty-four to the Clinton species, while in regard to 
the remaining eighteen it was impossible to hazard more than a 
guess as to which species the author had in mind. From among 
all of these references, therefore, more than one fourth were useless 
as a basis for accurate conclusions or inferences. 
In twenty-six references to what was clearly intended to mean 
Buthotrephis tenuis Hall, twenty-three referred to it as B. gracilis, 
but fortunately with more or less plain indications as to which 
species was meant, while in the three remaining references only 
was it called B. tenuis. 
Finally, attention is called to the fact that in accordance with 
our accepted rules of nomenclature the binomial Buthotrephis 
gracilis Hall, 1847, by reason of priority of publication, must be 
applied to the Trenton species, and the name B. tenuis, which he 
subsequently proposed for it, in 1852, becomes merely a synonym. 
Further, his transfer of the Clinton species, Fucoides gracilis, to 
the genus Buthotrephis, in 1852, required that this species be 
renamed, for the reason that the original specific name, gracilis, 
had been previously combined with Buthotrephis to represent the 
Trenton species. As this has not heretofore been done, so far as 
I am aware, the name Buthotrephis Hallii is now proposed for the 
Clinton species, in honor of the founder of the genus. 
