296 The American Geologist. November, 1904. 
In New Jersey the fragments of Balanus have been referred 
to B. protcits Conrad by Prof, R. P. Whitfield. These should 
undoubtedly be called B. coiicaz'us Bronn. In Whitfield's 
paper, Mollusca and Crustacea of the Aliocene of Xew Jersey, 
(Monograj)h xxiv, U. S. G. S.), there is one thing to which 
attention may be called. On p. 141 he says, "No entire indi- 
vidual of this species has been obtained from the New Jersey 
deposits, so far as I am aware ; but numerous separated plates 
are in the collection at Rutgers College." These sjDecimens, 
which were from near Shiloh, N. J., are figured, PI. xxiv, figs. 
18-23. In plate iv. fig. 8, on the ear at the left of the shell 
of Vola hnmphrcysi Conrad, there is figured attached an en- 
tire specimen of Balanus. This shell was also from near 
Shiloh, N. J. This illustrates the ease with wliich barnacles 
and other attached forms may be overlooked. 
Although there are minor dififerences in the shell due to 
attachment, there are, nevertheless, certain variations in this 
species not due to this entirely. Darwin figures both smooth 
and plicated specimens of B. concaznis. In American speci- 
mens there is the same variation. On a single valve of Pecten 
chiirnciis both forms were found. Several had four or more 
prominent radial plications on each of the parieties, another 
form of which there were several were perfectly smooth ex- 
cept for the lines of growth which were slightly raised. Such 
dififerences at first glance would seem to give definite varietal 
distinction but in a considerable amount of material it has been 
impossible to carry this difference beyond the early growth, 
both forms becoming roughened and rugose in further growth. 
In both forms there seems to ha no appreciable or constant 
difference in the opercular valves. The Gay Head specimens 
were of the smooth type. 
From the preceding it seems that we should adopt the 
earlier name of Balanus concaviis Bronn for the common spe- 
cies of barnacle found m the Aliocene from Gay Head south- 
ward through New Jersey, JNIaryland, Virginia, etc., instead 
of the commonly used name B. pvoteus Conrad. 
Boston Society of Natural History, 1904. 
