278 
PACIFIC SCIENCE, Vol. XI, July, 1957 
Mangrove roots 
Other 
Relation to substrate 
Buried (depth) 
Attached (method) 
Living in crevices, crannies, potholes, tide- 
pools 
Burrowed (e.g., in coral) 
Other 
Relation to tide 
Intertidal 
Above high tide line (distance) 
Below low tide line (depth) 
Type of water 
Active breaking surf 
Surging water 
Calm, protected water 
Other 
Living habits observed 
Solitary or gregarious 
Nocturnal or diurnal 
Method of feeding 
Food (algae, detritus, other organisms— 
preserve for identification) 
Method of locomotion 
Associations with other organisms (if any — 
preserve for identification) 
Apparent relationships 
Parasitism 
Commensalism 
Accidental 
Reproduction 
Breeding habits 
Egg-laying procedure 
Egg protection or brooding habit (e.g., 
egg case of Natica or brooding habit 
of Quoyuld) 
Enemies observed 
Fish 
Birds 
Mammals 
Invertebrates (e.g., starfish, other mollusks) 
The living mollusk 
Appearance, particularly color which fades 
with preservation 
Collect soft parts for anatomical study 
During the present study it was realized 
that a single collection by a single worker is 
likely to give a misleadingly circumscribed 
picture of a fauna, owing to individual meth- 
ods and interests. For instance, one person 
may collect mainly along the shore while 
another collects principally by diving off- 
shore. It is believed that the present approach, 
that of compiling information from several 
collecting methods and viewpoints, is a better 
one. Since these collections include species 
from many ecologic zones, a summary of the 
data of their several collectors presents a more 
realistic view of Micronesian gastropod eco- 
logy than would be likely to result from the 
notes or efforts of a single collector. 
In drawing up the geographic ranges, it 
became obvious that there are several faunal 
breaks in the Indo-Pacific region. Time was 
not available for analysis of these divisions 
but the basic data are included in the hope 
that other investigators may take it up. Par- 
ticularly apparent, however, was the fact that 
although many species range widely from east 
to west, almost none of the species occurred 
farther north than southern Honshu Province, 
Japan, or farther south than northern Aus- 
tralia. Breaks recognized are almost certainly 
related to temperature patterns and ocean 
currents. 
It was observed that many species whose 
geographic distribution is extremely wide are 
recorded as having pelagic larval stages (for 
instance many of the Cypraeidae and Cyma- 
tiidae, e.g., Cypraea isabella and Cymatium 
chlorostomum ) . It would be of great interest to 
learn the length of these free-swimming larval 
stages. Again, it was intended to draw up 
patterns of zoogeographic distribution and 
to correlate them with what is known of 
larval types, but here, too, lack of time pre- 
cluded such analysis. 
Throughout the study, the occurrence of 
each species around atolls, high islands, and 
continental shores was noted. The results for 
a few species (e.g., Trochus maculatus , Nerita 
