408 
of by the mixed character of the deposit, some of the shells being* 
Tinsuitable for such a purpose“. 
It can not precisely be deduced, neither from W. Spotswood 
Green’s narrative of the cruise nor from Nicholl’s report on the 
molluscs from the Expedition, how many dead shells occurred on 
the Rockall - banks, but below is named all the dead shells occur- 
ring during the whole Expedition together with Nicholl’s remarks 
about them: — 
Anomia patelliformis, Linné. 100 fathoms. 
Pecten islandicus, Muller. 100 fathoms. Two valves, probably 
semifossil, one of which, however, has a 
recent appearance. 
Pecten tigrinus, Muller. 100 fathoms. Two valves. 
Lima loscomhii, G. B. Sowerby. 100 fathoms. One valve and 
portions of two others. 
Mytilus modiolus, Linné. 100 fathoms. Dead valves. 
Cardium echinatum, Linné. One valve. 
Astarte sulcata, da Costa. 190 fathoms. Dead valves. 
Dosinia lineta, Pultenay. 100 fathoms. Single valves. 
Venus casina, Linné. 100 fathoms. Three left valves, dead. 
Venus fasciata, da Costa. 100 fathoms. One valve. 
Mactra solida, Linné, var. elliptica. 100 fathoms. Single valve. 
Thracia papyracea, Poli, var. villosiuscula. 100 fathoms. 
Portion of right valve. 
Mya truncata, Linné. 100 fathoms. Portion af valves, dead. 
Saxieava rugosa, Linné, var. arctica. One specimen, with the 
two valves united, and single valves. 
Trochus millegranus, Philippi, 120 fathoms. A dead specimen. 
Bueeinum undatum, Linné. 100 fathoms. A broken shell. 
Bueeinopsis dalei, J. Sowerby. 120 fathoms. Two dead shells. 
It is mueh to be regretted that Mr. Spotswood Green, in 
making the occurrence of these shells the foundation of a sinking 
hypothesis, has not at the same time tried to determine the vertical 
