BIVALVIA. 41 
5. Pecren pupiicatus, J. Sowerby. Tab. VIII, fig. 10, a—c; and Tab. X, fig. 3. 
Pecten Dupuicatus. J. Sow. Min. Conch,, t. 575, 1828. 
~- -- Morris. Cat. Brit. Foss., p. 174, 1854. 
Spec. Char. LP. testa orbiculari, depressd, radiata ; valvé dextrd sublevigatd ; altera 
costellatd ; costellis numerosis, imbricatis ; auriculis subequalibus. 
Shell orbicular, depressed, radiated ; one valve nearly smooth or with obsolete cost, 
the other with thin rounded ribs, 14 to 16, imbricated, increasing with age by the interpo- 
sition of an additional rib ; auricles nearly equal. 
Diameter, 14 inch. 
Localities, Highgate, Primrose Hill (Wethereil), a, 6, f, Haverstock Hill, c, Muswell 
Hill (Edwards). 
A strongly marked and ornamental species, and in the living condition probably a 
handsome shell. The specimens in cabinets are by no means abundant, and rarely in good 
condition. Mr. Sowerby, in ‘ Min. Conch.,’ represents one of his valves as quite smooth. 
In all Mr. Edwards’s specimens, the right valve has more or less depressed or obsolete costze, 
and as many as thirty of these faint rays may be counted, and these are distinctly visible in 
the interior. The left valve is ornamented with about sixteen thin, rounded, and imbricated 
rays on the younger shell ; these are doubled, and again doubled, as the shell increases in 
size, by the interposition of a rib ; they are all closely and regularly imbricated, but not the 
interspaces. 
6. Pecren mponevs, 8. Wood. Tab. VIII, fig. 9, a, 4. 
Spec. Char. P. testé inequivalvi ? suborbiculari, subdepressd, equilateral, costatd, et 
concentricé squamulatd ; costis 18-15 elevatis, magnis, subquadripartitis ; auriculis, equali- 
bus radiantibus. 
Shell inequivalve? suborbicular, somewhat depressed, equilateral, costated, and 
concentrically striated; ribs 13-15, elevated, large, and ridged; auricles equal and 
radiated. 
Diameter, 1+ inch. 
Localities. Hill Head, Stubbington (Fisher), Brook near Lyndhurst (Zdwards). 
This is an ornamental shell, and appears quite distinct. It was first discovered by 
the Rev. Osmond Fisher, who has obtained about a dozen specimens from the first locality, 
and Mr. Edwards has very recently added three to his cabinet from the latter. 
In well-preserved specimens, the ribs are ornamented with one elevated and two lateral 
ridges, dividing the surface of the rib into four portions ; the interspaces are about as broad 
as the ribs themselves, in which a ray or two may occasionally be seen on the outer or 
> older portion of the shell; the surface, when perfect, is ornamented with regularly concen- 
6 
