2 
numerously and less prominently ridged, the decussating 
lamella imbricated, and the corrugation more definite and 
oblique ; umbones acute. Right valve rather more convex, 
radiating ribs broader and flatter, and with concentric imbri- 
cated lamellae becoming somewhat prominent towards the 
margin ; anterior auricle strongly imbricated, the lamelle being 
irregularly raised on the upper margin ; posterior auricle with 
ridges closely armed with nodules or short blunt spines. 
Interior of the valves suffused with golden orange colour. 
Ligamentary pit small, triangular. 
Height, 35; width, 35 ; depth, 8 millim. 
Hab. :—Vasco da Gama, False Bay, N. 71° E, 184 miles ; 
depth, 230 fathoms ; bottom, stones. 
Of this beautiful species only one specimen has come to 
hand. The shell is of a very light, semitransparent substance, 
delicately tinted, having somewhat the general aspect of the 
C. Septemradiatus of the northern seas, but more numerously 
ribbed. The entire surface is roughened by close-set, 
imbricated ridges and fine strie, and the auricles are 
elaborately sculptured, particularly the posterior of the left 
valve, which, in addition to the imbricated cross bars, shows 
a peculiar arrangement of oblique granose striz. 
CHLAMYS FULTONI, n. sp. (Plate VI., fig. 5). Shell nearly 
orbicular, rather thin, compressed, equivalve, dull purplish- 
brown, irregularly interrupted with white markings. Auricles 
rather large, slightly unequal, posterior rectangular, anterior 
slightly laterally produced above and sinuous below. Valves 
furnished with 17 rounded, rather elevated equidistant ribs, 
the interstices being about the same width as the ribs, and 
regularly concave, without radiating strize ; both ribs and inter- 
stices are traversed by thin lamellae, which are squamosely 
raised on the ribs, particularly on the lateral ones. The right 
valve is somewhat smoother and lighter in colour, but other- 
wise presents the same character as the left. The anterior 
auricle of the right valve is strongly laminated, otherwise they 
are regularly costate. 
Height, 33; width, 34; depth, 11 millim. 
Hab. :—Amatikulu, Conical Hill, N.W., 7} miles; depth, 
26 fathoms; bottom, mud. 
The shells of this species vary considerably in pattern ; while 
in the type the white markings are rather large and few, in 
some the white predominates. In general style the shell some- 
what resembles C. ¢ranquebaricus, Gmelin, but it is broader in 
form, and has less numerous ribs, with no signs of longitudinal 
strie or riblets between them. 
