CRUSTACEA. 
215 
ranges of plates appears to be a matter of uncertainty and probably also of 
variation. Turrilepas Wrightianus, De Koninck, has four ranges and Barrande 
has expressed the impossibility of ascertaining from his specimens of Plumulites 
the exact number of these rows, regarding it as not less than four and rarely 
so few. In Lepidocoleus, Faber, there appear to be but two ranges of plates. 
In none of these genera has the character of the upper extremity of the animal 
been ascertained. Strobilepis spinigera may present a similarity to Turrilepas 
{Plumulites) in the numerical arrangement of its parts, but it presents an 
association of characters which separate it from either of those genera. In 
recognizing the cirriped character of this fossil, it is difficult to conceive how 
such a body, capped at the anterior extremity by a circular conical plate over 
which the adjacent plates are lapped, could have served as anything but the 
capitulum of the animal. There is no such difference in the character of the 
plates as would allow some of them to be regarded as peduncular and some as 
capitular, and no evidence that any scaly peduncle was attached beneath the 
plates. On the contrary the whole association of plates appears to represent a 
simple and uncomplicated primary type of lepadiform capitulum, less condensed 
and modified than in recent representatives, Scalpellum, Lepas, Ibla, etc. 
Distribution. Hamilton group. In the upper shales near Menteth’s Point, 
Canandaigua lake. 
TURRILEPAS, Woodward. 1865. 
Turrilepas flexuosus, n. sp. 
PLATE XXXVI, FIG. 1. 
A SINGLE minute plate is characterized by the following features; Outline 
obliquely lanceolate ; nucleus apical; a longitudinal furrow, lying just behind 
the middle line of the valve, begins at one-third the distance from the apex 
to the basal margin, becoming broader and deeper as it proceeds, its slope 
on the anterior side being much stronger and more abrupt than on the 
posterior. 
