Structure of Paleozoic Barnacles. — Clarke. 137 
THE STRUCTURE OF CERTAIN PALEOZOIC 
BARNACLES. 
By J. M. Clarke, Albany, N. Y. 
(Plate VII.) 
The courtesj' of Mr. Clifton J. Sarle, of Rochester, N. Y., in 
placing in my hands for examination a nearly, if not quite 
entire example of the peculiar cirripede genus Lepidocoleus, 
has afforded me an opportunity of elaborating its structure 
and indicating its relations to some other early forms of lepa- 
doid barnacles. 
The detached plates of such animals seem to be pretty 
widely diffused through Paleozoic faunas. Under the names 
Turrilepas and Plumvlites they have been described by various 
writers, from the Trenton group of Canada, the Hudson River 
group of Ohio, the Wenlock and Dudley limestones, the 
etages D and E of Bohemia, the Corniferous limestone of the 
lower Devonian, the Hamilton shales of the middle Devonian 
in New York, and the Cleveland shale of the Upper Devonian 
of Ohio. Yet only in isolated instances have these plates 
been found together so that any definite conception can be 
obtained of the form of the structure to which they belong. 
Dr. Henry Woodward has given figures of the most complete 
specimens yet known. In describing the genus Turrilepas* 
he based his account upon well preserved examples of the 
species previously known as Chiton wriyhtianus de Koninck, 
a Dudley fossil. One of the specimens figured in this paper 
is apparently complete and undisturbed (pi. 14, fig. 1/?), but 
it is stated to have been received after the reading of the 
paper and is in consequence not specifically mentioned in the 
description. This specimen indicates an elongate strobile- 
shaped body constituted of overlapping subtriangular plates 
arranged in not less than four vertical rows, in two of which 
the plates are of much larger size than in the others. Dr. 
Woodward recognized the probability that "the two broad 
rows of intersecting plates correspond with the lateral rows 
of plates, and the two minute rows | shown in his figures Ic, < 
and h] with the carina] and rostral series along which the 
specimen seems more readily to have divided as in the case of 
LoricuXaP No better specimens of this genus have been des- 
*Quart. Journ. GeoJ. Soc, 1865 ? p. 48(5. pi. 14. 
