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the dorsal side of the anterior part, which is finely striated in both 
directions ; in the epidermidal laminz, which are beautifully serrated ; 
and in the integumental covering of the dorsal edge, which is divided 
into four parts. 
Collected by Capt. Ince, R.N., in coral rocks at Rain Island, Torres 
Straits. 
8. Pu. muutistriata, Thes. Conch. Pl. CIV. f. 35, 36. 
9. Pu. vatissrma. Ph. testd subquadratd, subcompressd, apertd, 
antice angulatd posticé truncatd ; costis moniliferis radiatis et 
lineis concentricis cancellaté ; umbonibus subcentralibus mar- 
gine dorsali refiexo. 
A wide, rather flat shell, widely gaping in front, and truncated at 
the posterior extremity, with radiating ribs fornting knots on the raised 
lines of growth. It appears to be without accessory valves. 
Taken in Manilla Bay ; Cuming. 
10. Pa. sparnunata. Ph. testd elongatd, clausd, oblique divisd ; 
parte anticd radiatim costatd subangulatd ; parte posticd con- 
centrice leviter striata, subtruncatd, ad margines integumente 
protectd, ad terminus in cyatho-corneo, luteribus spathuliformi- 
bus, productd: ad umbones laminis duabus equalibus posticé 
bilobatis, antice elongatis. 
From New Zealand. 
Puotas Catva (Sowerby, Proc. Zool. Soc. 1834), Pl. V. f. 4. 
I wish to call the attention of the Meeting to a remarkable speci- 
men of Ph. calva in situ, which may be considered as bearing, in 
some degree, upon the boring question in a manner somewhat un- 
favourable to the ‘rasping’ theory. In this specimen the animal 
has lined the anterior narrow end of its hole with a thick laminated 
tube, formed not of shelly matter, as in the case of Pholas tubifer, of 
which I figure a specimen ia situ, but of the same material as the 
stone in which it has burrowed, and bearing every appearance of a 
reformation of its substance by precipitation, after having been dis- 
solved by a chemical agent. The structure is far too fine to have 
been formed from any débris which could be the result of merely me- 
chanical action. 
The specimen of Ph. tubifer, Pl. V. fig. 5, in my father’s collec- 
tion, shows in a remarkable manner the fitting of the hole to the shape 
of the shell, which is not symmetrical, and could not turn in the 
slightest degree. 
