154 MOLLUSCA FROM THE CRAG. 
3. CARDIUM NoposuLUM, S. Wood. Tab. XIII, fig. 3 a—e. 
Carpium NoposuLum. S. Wood. Catalogue, 1840. 
Spec. Char. Testé minutd, subcirculari, parum inequilaterali, compressiusculd, tenui; 
costatd et nodosa ; costis 30 convewxis, papillosis, brevibus, et obtusis. 
Shell small, subcircular, slightly inequilateral, rather compressed, thin, costated, 
and nodulous; ribs about 30, convex, and studded with numerous short, obtuse papillz. 
Diameter, ths of an inch. 
Locality. Red Crag, Sutton. 
Two or three specimens only of this shell are in my cabinet. 
There are several species to which this shell bears considerable resemblance, but to 
no one does it appear to accord in all its characters ; it must, therefore, remain for the 
present with the provisional name attached to it in my Catalogue. In form and general 
outline, it is somewhat like the figure of C. pennulatum, Conrad ; but from the description 
of that shell by Dr. Gould, ‘Invert. Massach.,’ p. 91, it has only twenty-six ribs, and 
an angular ridge on the posterior side, with other characters assigned to nodosum, 
corresponding precisely in description to that species, and in like manner differing from 
ours. 
Card. minimum, ‘Phil. En. Moll. Sic.,’ also resembles it in many characters, but from 
his description must be distinct, as there appears a great difference in the form of the 
ribs, for that author speaks of his shell, p. 38, ‘‘ costis 30—32, planissimis.” 
Our shell may be more fully described as nearly equilateral, the posterior side a 
trifle the larger, very slightly convex, or less tumid than the generality of these small 
species, somewhat rounded on both sides, rather the less so posteriorly ; the distin- 
guishing character is in the ribs, which are, at least, 30, not flat, but convex, with 
a wide space between each, and the centre of these ribs only are covered with short, 
narrow, obtuse, nodules ; those upon each side, more especially on the posterior, are 
smaller than upon the middle of the shell. The interstices between the ribs are broad, 
deep, concave, and smooth. Card. suecicum has a like number of ribs, but is not 
smooth between them, is more inequilateral, and has vaulted scales. Card. papillosum, 
Poli, has a less number of ribs, and is otherwise different. 
4. CARDIUM STRIGILLIFERUM, S. Wood. Tab. XIII, fig. 5 a—d. 
Carpium ELonGatTuM. SS. Wood. Catalogue, 1840. 
Spec. Char. Testa minutd, ovatd, transversd, valdé inequilaterali, tumidd ; costis 24 
elevatis, planiusculis, papiliferis, papillis squamaformibus, sulcis magnis punctatis, vel trans- 
verse unbricatis. 
Shell small, ovate, transverse, very inequilateral, tumid, with about twenty-four 
elevated ribs, flattened on the top, and ornamented with vaulted scales or tubercles ; 
spaces between the ribs wide, with elevated concentric ridges. 
