Identity of Pholadidea papyracea and Pholas lamellata. 9 
and only consist in the circumstances, that during the summers 
of 1848-9 I sedulously for several weeks examined the Pho- 
lades, both in situ and in the closet, when after a careful inves- 
tigation I arrived at the same conclusions with respect to the 
boring agents of the bivalves as Mr. Hancock ; and I have the 
notes of them now by me, written before Mr. Hancock’s publi- 
cation, which I intended to lay before the public; that gentle- 
man has anticipated me, the whole merit is his, and I cordially 
apply to him the motto, “ Palmam qui meruit, ferat.” I will now 
state some facts which perhaps have escaped Mr. Hancock’s at- 
tention, corroborative of his positive discovery. 
I revert for a moment to the consideration of the identity of 
Pholadidea papyracea and the Pholas lamellata of authors, on 
which point Professor Forbes and Mr. Hanley, in the ‘ British 
Mollusca,’ have concurred, having in some measure relied on my 
authority communicated many years ago. The investigation in 
the last summer (1848) was undertaken by me both with the 
view of making an attempt to discover the terebrating powers of 
the Acephala, particularly of the Pholades, and for further proofs 
of the identity of the two forms styled by authors Pholadidea 
papyracea and Pholas lamellata. 
In the course of my examinations I was startled by the great 
variations in the organs of the two forms of this Pholas, which, 
twenty years ago, when I first examined this species, appear not 
to have so rigorously excited my notice; doubts arose in my 
mind, that I might be wrong in my former determinations of 
identity, and I wrote to Dr. Battersby to express them to him 
and Mrs. Griffith, both of Torquay ; the latter a lady naturalist, 
who has taken great interest in this question ; but in the present 
summer of 1849, after a continued investigation of fourteen 
weeks, my doubts were dispelled, and I stated personally to Dr. 
Battersby, that after a careful review of all the evidences that pre- 
sented themselves, I reverted to and relied on my original deter- 
minations of identity of the two forms of Pholadidea papyracea. 
This change of opinion arose from the observation that in the 
adult Pholadidea papyracea, the mottled appearance of the belly, 
so dissimilar to that of the form Pholas lamellata, was due to the 
extension of the reproductive membranous organs of the ovarium 
and the spermatozoa, occupying the space usually appropriated 
to the foot, which I found had disappeared. This anomalous 
appearance excited my attention, and the reflection that with 
nearly absolute ceteris paribus, in the generalities of all the Pho- 
lades, there was no substantial reason why one species should 
always be deprived of the foot, when all the others possessed that 
appendage, and as I had come to the conclusion, that it was 
the boring instrument, I felt assured that this anomaly was only 
