43 
Fam. CYPRINID^. 
OXHORN-COCKLE. 
IsocAUDiA COR, Liuiiseus. Heart-shell or Oxhorn 
Shell very strong, nearly spherical, heart-shaped, 
concentrically striated, equivalve, smooth, with a dark 
reddish-brown epidermis ; beaks very prominent and 
curled ; two primary teeth in the right valve, lying pa- 
rallel to each other ; in the left valve, the outer tooth is 
indented and is large, the other thin and laminar. The 
lateral tooth strong and elongated, situated under the 
ligament, which is external. 
This magnificent mollusk is very partially distributed, 
though plentiful in some places. Specimens have been 
sent to me from Dublin Bay, where I grieve to say they 
are getting very scarce, and also from Brixham, where 
they are highly prized by the fishermen. They do not 
however often bring them on shore, though they bring 
them up in the dredges, unless they wish to make a pre- 
sent of a dish to some friend, or know where they can 
dispose of them. They call them Torbay-noses,^’ and 
they are also known by the names of Oxliorn-cockles^^ 
and “ Heart-shells in France, coeur de bmuf, in Hol- 
land, zots-kappen, or fooFs cap, and at Naples, cocciola 
zizza, Mr. J. G. Jeffreys, quoting an interesting ac- 
count of Isocar dia cor, by the Rev. James Bulwer 
(who kept a specimen in a vessel of sea-water, and 
was therefore able to study the habits of the animal), 
given in the ^Zoological Journal,^ states, ^Ghat the 
animal appears insensible both to sound and light, as 
the presence or absence of either did not interrupt its 
movements, but its sense of feeling appeared to be 
