190 Mr. Jeffreys on British Mollasca. 



Dr. Lukis kindly sent me specimens from Guernsey in which the 

 tube is semiconcamerated at its narrower end or opening, as in T. 

 Norvagica. They were found in deal and teak wood. 



T. malleolus, i. 84. In cork, Plymouth Sound {Mr. Webster); 

 and with the last, in a log of deal balk which was cast up on the shore 

 at Guernsey {Dr. Lukis). Some of the valves sent me by Dr. Lukis 

 measure f ths of an inch in length, and are so similar in every respect 

 to those of T. bipennata that I am much inclined to doubt their 

 being distinct species, notwithstanding the difference in their calca- 

 reous styles or pallets. So little is known of the ceconomy of these 

 appendages, that it is possible that the very aberrant forms which 

 they exhibit in these two so-called species may be only a modifica- 

 tion of the same organ, depending on a difference of climate or 

 habitation, 



'""^holadidea papyracea, i. 1 23. This local and curious shell has 

 been found by Capt. Bedford in lumps of indurated clay which were 

 brought up on fishermen's lines from clayey ground, at a depth of 

 about 25 fathoms, near Lismore on the west coast of Scotland. One 

 of the specimens has the dried remains of the animal in it. In the 

 same matrix which contained the Pholadidea are firmly imbedded 

 fossil specimens of Nucula decussata, some of which retain their 

 epidermis. The last-named species is found living in the same lo- 

 cality. This association of species, which, in their recent state, are 

 regarded by some conchologists as being respectively characteristic 

 of northern and southern latitudes, is somewhat remarkable ; though 

 I believe the Pholas Vibonensis oiVhi\\^Y)\ (Enum. Moll. Sic. ii.p. 46, 

 t. 13. f. 5) is the young oi Pholadidea papyracea, while the other 

 species has been described and figured by Bronn as well as Philippi 

 under the names of Nucula sulcata and Polii — the first species as 

 a pleistocene fossil, and the last both as recent and fossil. The 

 lumps of clay appear to have been consolidated by a calcareous 

 deposit or infiltration, and they are as hard and compact as many 

 kinds of stone. Dr. Capellini informs me that an equally compact 

 kind of stone, which is considered to be pleistocene, and contains 

 fossil shells of that period, occurs at Leghorn, and is extensively used 

 for building. I have now (August 23) found the P. papyracea, as 

 well as the dwarf variety mentioned in the *-British Mollusca,' alive, 

 in small lumps of triassic sandstone which were dredged up from a 

 depth of 80 fathoms in the Irish Sea, oflF the coast of Antrim. I 

 may take this opportunity of observing that all the shells and other 

 animals which I took with the above have their colour quite as vivid 

 as the same species which inhabit a much less depth, or even the sea- 

 shore. Such is the case with Trochus zizyphinus. Tapes virginea, 

 Natica nitida, Munida Ro7ideletii, Pandalus annulicornis, and a 

 small streaked Actinia. It appears to be a popular error, that at 

 depths exceeding 50 or 100 fathoms, colour becomes less bright or 

 even evanescent. 



Sphsenia Binghami, i. 190. Not uncommon in rolled pieces of 

 chalk, as well as among the roots of Laminaria digitata, on the 

 north-eastern coast of Ireland. I much doubt its having the power 



