BALCII: LIST OF MARINE MOLLUSCA. 
35 
(3 fathoms?) stations 80% are present, while from the deeper 
waters we have only 59%. But a cross analysis according to other 
characters shows a very different result, for from all the muddy 
habitats we have 68%, from gravelly and shelly 68%, from 
woodwork and rocky 68%, while from sandy we have 89%. This, 
last, however, should be thrown out entirely, since Professor Ver- 
rill gives very few species as characteristic of sandy shores and 
bottoms and those few are common forms of wide distribution, all 
occurring at Coldspring Harbor in mud. 
The conclusion is that the molluscan fauna of Goldspring Har¬ 
bor, in spite of the well-marked character of the place as “ muddy,’’ 
is determined, not at all by that character, but preponderate 
ingly by the depth of water and by the factors included in the 
“ enclosedness ” of the place — that is, I suppose, by the tempera¬ 
ture, the tranquility, the specific gravity, the per cent, of organic 
matter, etc. It looks as though the various species would manage 
somehow to be represented on almost any stretch of shore or bot¬ 
tom provided only the water conditions be right. This conclusion 
premises that shore and bottom were relatively equally explored, 
which was probably the fact. My conclusion is, of course, not 
inconsistent with Professor Verniks analysis, as his groupings 
would still represent all they were intended to, viz., optima. 
The Mollusca found were distributed, omitting doubtful occur¬ 
rences or identifications as follows : — 
Cephalopoda , 
Decapoda, 1. 
Gasteropoda , 
Amphineura, 1. 
Prosobranchiata. 
Docoglossa, 1. 
Ptenoglossa, 1. 
Taenioglossa, 16. 
(lymnoglossa, 8. 
Raehiglossa, 9. 
Toxoglossa, 1. 
1 . 
1 . 
r 
36. 
Opisthobranchiata. 
Tectibranchiata, 2. 
Ascoglossa, 1. 
Nudibran chiata. 
Kladohepatica, 4. 
Holohepatica, 2. 
Pulmonata. 
Bassomatophora, 2 
Pelecypoda , 
Protobranchiata, 3. 
Filibranchiata, 6. 
Pseudolamelli- 
branchiata, 2. 
E ula m ellibran ch i - 
ata, 23. 
' 9 - 
o 
y 34 . 
Total, 63 genera, 83 species. 
