320 MOLLUSCA. 
~ 
sight to be smooth, but on closer examination, the lines are found to 
cross over from side to side in a curved manner, so as to form a most 
delicate web, and causing the granules sometimes to appear to have a 
zigzag arrangement; posterior valve large, with a prominent central 
umbo, the marginal portion with the raised, interrupted, branched 
radiating lines; anterior valve with fine, radiating lines, sometimes 
divaricate ; whole surface covered with fine punctures. Margin broad, 
pale, with dusky patches, most minutely granulated. Interior yel- 
lowish-green. Marginal ligament broad, pale, minutely granulated. 
Length an inch and a half; breadth five-eighths of an inch. 
Inhabits New South Wales. From Mrs. Mitchell. 
In general appearance, especially in the sculpture along the back, 
it is like a shell figured in the Conchological Illustrations by Mr. 
Sowerby, under the name of C. solea, and afterwards said to be a 
variety of C. Indicus. But it has no ramose sculpture on the lateral 
areas. 
Figure 428, back of the shell; 428 a, details of the sculpture, mag- 
nified. 
CuHITON PLATESSA (Gould). 
Testa parva, tenuis, elongato-ovalis, transversim arcuata, citrino-oli- 
vacea, ubique minutissime punctata; areis lateralibus parvis, viz 
elevatis, lineis duabus vel tribus inconspicuis striatis ; areis central- 
bus hnets confertis acutis granulatis arcuatim decussatis ; valva pos- 
tica magna, obscure radiata ; margine virente, fusco tessellato, minu- 
tissime granulato: intus ceruleo-virescens. 
Chiton platessa, Goutp; Proceed. Boston Soc. Nat. Hist., ii. 143. 
July 1846. Expedition Shells, 4. 
SHELL rather small and thin, oval, much elongated, transversely 
arched, of a yellowish olive colour, minutely punctured in quincunx 
at every part. The valves are flattened, without beaks or keel, the 
tips denuded; lateral areas very small, striated with two or three 
radiating lines ; central areas with very fine, sharp, granulated, longi- 
