SCALPELLUM. 43 
13. ScaLPELLUM TUBERCULATUM. ‘Tab. I, fig. 10. 
S. valvarum lineis tenuibus, tuberculatis, elevatis, ab apice radiantibus: carine tecto 
transverse leniter arcuato, et parietibus striatis: scuti umbone prope in medio marginis 
occludentis posito, costis duobus ab umbone ad angulum basi-lateralem, et ad basalis marginis 
medium decurrentibus. 
Valves, with fine, tuberculated, elevated lines, radiating from their apices: carina, with 
the roof in a transverse line, gently arched, and with the parietes striated: scutum, with 
the umbo placed nearly in the middle of the occludent margin, with two ridges running 
from the umbo to the baso-lateral angle and to the middle of the basal margin. 
Chalk Detritus. Charing, Kent. Mus. Harris. 
Through the kindness of Mr. Harris, I have examined several valves, which I believe 
to belong to the same species: the specimens were found in the chalk detritus, and, 
therefore, may have come from the Upper or Lower Chalk or Chalk-marl; but more 
probably from the Upper Chalk. With respect to the scuta and terga I have scarcely any 
doubt, from certain peculiarities, that they belonged to the same species; but with regard 
to the most important valve, the carina, I cannot feel quite so certain: when the latter is 
so held, that the parietes are not visible, it has a very close general resemblance to the same 
valve in Pollicipes rigidus. In the carina, the present species comes closer to S. arcuatum 
than to any other species; in the other valves, especially in the singular scuta, it departs 
widely from that and all other known fossil forms, with the exception of S. (?) crete, of 
Denmark. All the specimens which I have seen are small; the carina being °2 long, and 
the terga less than -15 of an inch in length, in the largest specimens. 
consequence of this, the lines of growth make a different angle, on the opposite sides, with this ridge: 
as the valve has been somewhat worn, it is possible that the carinal margin may have been more abraded 
than is apparent. Internally, it is seen that a considerable portion of the upper part of the valve projected 
freely ; beneath this, the inner surface is slightly convex, but smooth, and though the shell has been much 
worn, I doubt whether there ever existed ridges, as on the internal surface of the upper part of the terga 
in S. arevatum, to which valve this presents a close general resemblance. Length of tergum (when 
perfect), 1°2 of an inch. 
Carinal Latus (fig. 8, e, f) ; amongst the fossils from Kopinge (at which place the same species are found 
as at Kjuge), there is a valve, which I believe to be a carinal latus of a Scalpellum, and which, from its 
longitudinal ridges, more probably belonged to the present than to any other species: from its peculiarity 
it is in any case worthy of description, In form it is a segment, somewhat less than a quarter, of a circle ; 
of this segment, nearly half (I believe the upper half) has its end or circumferential margin much 
hollowed out, and its surface smooth: the other half has its periodical growth-ridges very prominent, 
and these are crossed by a few slight longitudinal ridges. One of the lateral sides (the upper, I believe,) 
is reflexed so as to form a prominent ledge; the other side is slightly inflected. 
