194 THE ZOOLOGIST. 
an hour, it is evident that countless numbers must annually be 
discharged into the sea. Whilst floating on the surface of the 
waves, the continuous motion of the water must in many cases 
remove the plug of clay, causing the shell to lose its buoyancy 
and sink to the bottom. In consequence the bed of the Mediter- 
ranean, for many miles to the southward of Sicily, is in all 
probability scattered over with the land-shells of that island, and 
a mixture of land and marine forms is being deposited at great 
depths. I forwarded a series of these drifted shells to Professor 
Luigi Benoit, who most courteously examined them, and informed 
me that they were common Sicilian species. Among the more 
abundant forms were Helix elata (var. turrita), Phil., Pupa doliwm, . 
Drap., Helix acuta, Miller, H. gregaria, Ziegler, H. sequenziana, 
Benoit, and Clausilia adelina, Benoit. 
Dead specimens of Helix lactea are sometimes found along 
the shores of the Quarantine Harbour of Valetta. 'This species is 
not indigenous, but is thrown overboard from the small craft that 
trade between Africa and Malta. The crews of these vessels use 
this snail as an article of food. I am indebted to Mr. Charles A. 
Wright, so well known in connection with the Ornithology of the 
Maltese group, for this observation. 
In the year 1867 Dr. A. A. Caruana, Secretary to the University 
of Malta, read before the Society of Archeology, History, and 
Natural Sciences of that island a report* on the Maltese Mollusea, 
prepared from the MSS. and collections of the late Mr. Giuseppe 
Mamo, who for nearly half a century was a sedulous cultivator of 
the science of Conchology, and a careful collector of the Mollusca 
of his native islands. The catalogue prepared by Dr. Caruana 
from the MSS. of Mr. Mamo is extremely useful to the student of 
Maltese Mollusca; but several of the names given are merely 
synonyms, and some species, such as Helix turrita, Phil., and Pupa 
polyodon, Drap., have been admitted to the list on insufficient 
grounds. A great assistance to the Maltese student is the local 
collection deposited in the Public Library of Valetta by Mr. Mamo 
in 1854, at the instigation of Sir William Reid, then Governor of 
the island. 
A very interesting pamphlet, entitled ‘ Dei Molluschi terestri 
e d’acqua dolce raccolti nello Arcipelago di Malta,’ was published 
* Enumeratio ordinata Molluscorum Gaulo-Melitensium cf the late Mr. Giuseppe 
Mamo. By A. A. Caruana. Malta, 1867. 
