5 
many hundred unknown shells and numerous marks of a 
scientific mind,—in Mr. Humphries’s collection, which 
had been for many years unopened when my brother pur- 
chased it and disclosed its riches. It is remarkable that 
both valves should always be found, and no substance ac- 
companying them to which they may have been attach- 
ed: but this is partly accounted for by the nature of the 
attachment, which would fail upon the death of the ani- 
mal, and by the elastic texture of the valves, which, as one 
is inclosed in or grasped by the other, would still hold 
together. We know of but one other specimen; it is a 
single individual attached to Nucula Ovum: both are 
filled with indurated clay. It is in the cabinet of John 
Hogg, jun., Esq., who obtained it near Whitby, from the 
Alum Clay. 
ORBICULA Humphriesiana. 
TAB. DVI.—fig. 2. 
Spec. Cuar. Conical, orbicular, marked with di- 
verging striz ; apex elevated, rather excentric, 
obtuse. 
Mucu resembling the O. norvegica; but it is a higher 
and more regular cone, is more deeply striated, and 
thicker. We do not know the lower valve. 
Found attached to Ostrea deltoidea (M. C. 111.) in Mr. 
Humphries’s collection, with a label marked “ Collin- 
son’s Sale, at Langford’s.’”’ We suspect it to come from 
the Oxford Clay at Shotover Hill. 
