GEOGRAPHICAL DISTRIBUTION. Moll . 55 
29 . Californian Region. 
California. Selenites cailata , n. sp., Mazyck. 
Pacific Province. 83 forms enumerated and many figured, with notes, 
by Binney. 
30 . Canadian Region. 
Labrador. Limax (2 species), Pupa , Zonites from Ungava Bay ; 
Dall (1). 
Ottawa. Exact localities of and notes on 42 species ; Latciiford. 
Marine Mollusca. 
Oceanic. Areas. 
The general subject of deep-sea Mollusca is treated by Dall (4). 
Large shells are rare in deep water, and those which occur are very 
dolicato ; nearly all aro thin and fragilo, with faint colours and delicate 
sculpture ; sometimes thin blister-like elevations are found on the shells. 
The tissues of the animals are soft and gelatinous. The greatest wealth 
of Mollusca is to be found in the archibenthal zone (“continental area” 
of Agassiz), intervening between the littoral and abyssal regions. The 
soft mud of the sea-bottom affording no resting-place for them, the 
stems of hydroids and the spines of echinids are used. Nearly all are 
flosh-eatcrs, living upon doad organisms, not on oacli other. There is “in 
the deep sea a very wide range of variation in form and sculpture within 
the specific limits of” what are termed “ the * flexible * species, and an 
almost complete uniformity over very wide areas of the forms which we 
may consider as inflexible species.” See also Perrier. 
Watson, pp. iv & v, sums up evidence of ‘ Challenger ’ collection regard- 
ing distribution. Depth has considerable influence in this regard, but 
temperature more : pressure is not so important. “ The occurrence 
of a living species in a fossil state will always justify the expectation of 
its having a wide local distribution, and vice versa? “ There are 
existing species whose distribution is universal.” There is “no proof 
. . . of progressive permanent and essential change in Molluscan 
development.” 
Many genera are mentioned by Chierciiia. See also Picaglia. 
Bathymetrical distribution of Cephalopoda discussed, and evidence 
adduced to show that certain forms ( Cirroteuthis , Bathyteuthis , Masti- 
goteuthis , &c.) are truly abyssal ; Hoyle, (1) pp. 230-234. 
Notes on deep-sea Chitons are given by Haddon ( 1 ) pp. 1-3 ; Lepto- 
chiton benthus , n. sp., comes from 2300 fathoms in the North Pacific, 
the greatest depth from which any member of the group has yet been 
recorded. 
Oceanic Mollusca of Gulf Stream ; see Yerrill, p. 592. 
List of species from coast of U. S. given by Bush (1). 
Atlantic Ocean. 3 new Pteropods; Boas, (2) pp. 80, 152, & 160. Mar- 
senia, n. sp., Bergh, (1) p. 16. 
