Pvn H,i I'UitlS

216 KELLIID.E.
Recluz Erycina Franciscana, and Loven Montacuta
tenella.
Mr. Robert
Among some small shells sent to me by
Dawson, and collected by him on the Aberdeenshire
coast, is a minute single valve, which I cannot identify
with any known species, whether recent or fossil. Its
shape is obliquely triangular, with rounded margins ;
is compressed, rather solid, glossy,
only by the lines of growth ;
it
and smooth or marked
the beaks are blunt and
not prominent; the hinge-line is small and straight;
the teeth somewhat resemble those in the right valve of
Montacuta bidentata, but they are much shorter and
nearly on a level with the hinge -line, the tooth on the
broader side being considerably larger and stronger than
the other; the inside is nacreous, with a plain margin.
The shell appears to be full-grown ; but its size is barely
one-fifteenth of an inch in length, and rather less in
breadth. If more specimens are found, I would propose
for this species the name of Dawsoni, as a fit compliment
to its discoverer, a zealous and intelligent con-
chologist.
When dredging at Falmouth in 1839 I obtained a
recent single valve of the species, which Searles Wood
described and figured in his Monograph of the Crag
Mollusca (Palaeont. Soc. Trans. 1850, p. 131,
tab. xi.
f. 3 a-c) as Montacuta donacina, from the Coralline
Crag at Sutton. I am, no less than Mr. Wood, quite
unable to say in what genus this curious shell should be
placed. My specimen is a right valve, and it has a
minute tubercular tooth on the longer side of a small
cartilage-pit. In shape it is a miniature Zenatia (a
genus founded by Dr. Gray), but having
ligament.
an external