3 f 
Marked for me by J. E. Gray, Esq. of Ilia 
j“ nt,sh museum. It is the largest of the British arose that 
nas come under rnv notice, measuring in its longest dia- 
meter one inch and four-tenths, and in breadth nine-tenths 
° an inch, figure of the rhumb across the hinge one inch 
and one-tenth; surface of the valves as if worn, liy the fric- 
,'on of opening in the cavity of the stone in which it was 
!?m u< led, and hence the vestiges of striae were but few. 
■jbout the middle of the free edges of the valves is a 
'acancy rounded oil - into a long oval; this portion, when 
valves are closed being filled by a semicalcareous oper- 
C " 11 111 formed on the summit of the tongue or protrusive 
°^gan. A border, of regular form and about one-tenth 
an inch wide, circles the free margin of the valves, being 
covered with short bristles in narrow lines. Some marks 
t lil . ese hairs appear on other parts, especially on the 
er minal angle of the opening. Colour dull yellow, bristles 
crown. 
Tl ■ 
'*> a " S ’ l *' e on ^- v s P ec ' men which l have met with, was found 
tfee Cav '*y originally formed by a Pholas in sandstone from 
P water, and was for some time alive in my possession. 
Qp PECTUNCULUS. 
*XiC CHARACTER: Shell orbicular, almost lenti- 
a r ' i' r ’ l ^ e . va * ves equal , sides almost equal, close. Hinge 
tvii I W,t ^ a ser ' os many, oblique entering teeth, the 
te Ul| | e ones obsolete, nearly obliterated. Ligament ex- 
erh- 8 '1 ' rllis gen,ls distinguished from area by its 
sir ,'- C "' ar i"°rm, alJ d by the hinge being arched instead of 
®n f'l’kk The teeth also are less numerous, more separate 
'list ar S cr 5 an( i they never gape. The beaks are not very 
anl a | nt ’ are a f w a >' 8 separated by an external, narrow, 
1L. arly furrowed, rather hollow facet, to which the 
^atnent is attached, ami which distinguishes the Pec- 
cu li front the genus Nucula ; the ligament of which is 
% P t>T ' nter ' or > 30(1 which has no facet between the beaks, 
p ‘LOSUS. Area P. Turt. Lin, A. Glycitneris. 
ft®?/ Brit. Zo., vol. 4, pi. 58. fig. 58. A. P. Mont. Test. 
Cor,, Vo1 ' B P- 13R - p ‘ p - Flcm. Brit. An., p. 4C0. 
•titon, and locally abundant. 
Cg A . NUCULA. 
] ar | ftIC CHARACTER : The shell transverse, triangu- 
jv, ^ ov ate or oblong, the valves equal, sides unequal ; no 
t 0 ,1 between the beaks; hinge linear, broken, many 
l en .. “> interrupted in the middle by an obliquely ex- 
d, )c ’“S spoonshaped pit; the teeth numerous, often pro- 
itack 35 Pectens ! the heaks contiguous, curved 
iu Se 7 arRs< Ligament marginal, and partly internal, 
ed in the pit or spoon of the hinge. 
