the “Cirripede”’ Lepidocoleus. 655 
and the second shell show certain narrow longitudinal de- 
pressions, but these are evidently due to compression. 
Another specimen (Pl. X. figs. 1-4) was in two pieces, 
which fitted together quite readily. The larger piece shows 
a column of eight plates and an impression of another plate, 
and this is presumably the specimen represented by Cowper 
Reed (1908, pl. xii. fig. 9) in an inverted position, although 
it is not easily recognised from the figure. The smaller 
piece, which consists of two columns, each of four plates, is » 
evidently the third specimen mentioned by Cowper Reed. 
These two pieces, then, together comprise twelve plates and 
an impression of another in serial order, and these plates do 
not appear to have been displaced in any way, so the length 
of the shell, which measures 21°7 mm., is probably the 
correct length of the piece preserved, and its greatest 
breadth is 5:0 mm. On the other side of the shell the 
lowermost four plates are shown, but since they are much 
flattened, they do not show well on the broad “fixed”? margin; 
but above these, in the middle of the specimen (Pl. X. 
fig. 2), the plates of the two series are seen to be in close 
apposition with little or no alternation. On this same 
side of the specimen, the lowermost three plates are broken 
away towards the narrow “free” margin, and, since the 
fourth plate is entire, one can measure the degree of overlap. 
The fourth plate has a breadth of 4°7 mm., and a length of 
2°7mm., and the third plate overlaps this to the extent of 
1-2 mm., leaving 155 mm. exposed. The ornament of tlie 
plates consists of fine growth-ridges comparatively wide- 
spaced, numbering about four to a millimetre, and between 
these are from five to six slightly finer ridges, which give to 
the shell a peculiarly closely and regularly ridged appearance. 
Although the main ridges are clearly seen on both specimens, 
the finer ridges are well preserved only on this one, where 
they are very clearly shown on the lowermost four plates 
of the right-hand series ; an enlarged view is given of the 
two lowest plates (Pl. X. fig. 3). | 
Comparison with other species.—L. graye is distinguished 
from other species by its exceedingly fine and numerous 
growth-ridges, but it would appear to differ also from the 
known Ordovician and Silurian species in the length of 
the shell and the number of plates. ZL. graye has at least 
sixteen plates to an incomplete shell, which would have 
measured at least 25 mm. L. jamesi (Hall & Whitfield), 
from the Hudson River Group (Ordovician) of Cincinnati, 
is said to have only fitteen plates in a complete shell, and 
this has only a length of about 12 mm., less than half 
