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Area 6 is basically a flat coral plain with a silty bottom with intermittent medium and large coral heads and a few scattered
coral slabs. A great deal of the area was ruined for shelling when I blasted the mooring trenches across the area to
facilitate anchoring the tankers in this mooring. The western end and seaward side still offer excellent collecting for scuba
divers.
Area 7 is nearly a continuation of Area 6 except for the greater amount of thick coral rubble. Collecting in this area is not
as good and is limited to the more common shells. The seaward edge, in about 20 fathoms, will produce many of the more rare
bivalves such as listed for Area 6.
I have a Cypraea arabica niger Roberts (the racial name is in accordance with the Schilder's classification) which was
collected on the rusty hulk of a ship at New Georgia, Solomon Islands, a Cypraea mauritiana calxequina Melvill and Standen
collected on a sunken Japanese ship in Rabaul Harbor, New Britain by Harry Reiek, and a Cypraea maculifera Schilder collected
by John Souder near a rusty sunken ship at Berlin Island in the Marshall Islands. All of these are melanistic because of the
rust in the nacre which evidently was absorbed by the mantle and deposited in the nacre. The color of the maculifera was the
least affected and that of the mauritiana the most affected as the dorsum is a deep reddish brown. This did not effect the
base of any except the arabica, and on it there was some traces of the rusty color that extended a little on the base on each
side. This lack of effect on the base could possibly be another flaw in Cernohorsky's theory.
Conchologists have been puzzled for many years as to why cowries in certain areas are subject to melanism and rostration.
Some of the old time conchologists thought some were new species, and unfortunately some were described. For example, Cypraea
arabica niger was described as a new race.
Melanism and rostration rarely occur in Japan; rostration is rare in Okinawa and Torres Strait, and melanism never occurs in
Okinawa and Torres Strait to my knowledge. It is puzzling that the most complete melanism and rostration combined occur in
New Caledonia and Queensland both of which are near the Tropic of Capricorn. It is by far the most frequent in that latitude
too. It is a mystery why some species that live in the two areas most affected are never rostrate or melanistic.
I will diverge from the subject to some extent in the next paragraph, but it does concern the unusual in cowries.
Unknown factors in the environment seem to influence the size, color, and shape of cowries causing ecological variations and
aberrations. I have seen a Cypraea miliaris diversa Kenyon (=metavona Iredale) which was collected by Alex Schelechoff in
Moreton Bay, Queensland, which is so suffused with a uniform layer of white enamel that only by close examination can one
discern the dorsal spots. Alex deserves credit for noticing this detail as very few collectors would have noticed this. At a
glance it appears to be Cypraea eburnea Barnes.
The illustration [above] shows two Cypraea scurra Gmelin collected off Barbers Point. The specimen at the left has a complete
covering of an olive green color. As far as can he determined, the nacreous covering of the shell is identical to that of the
normal scurra on the right. Other collectors must have also collected similar shells. Is this melanism or a diseased
condition?
The first article in this series dealt with the collection of a live Golden Cowry, practically on order, by Francisco E.
Lahora of the Southern Philippines. This shell was requested by Dr. Alison Kay, General Science Dept., University of
Philippines, who wished to examine the soft parts microscopically. In the course of corresponding with Mr. Lahora, many other
interesting facts developed. We emphasize the word facts because in his letters Mr. Lahora insisted that he would give only
details which he could substantiate.
Unless the Philippines are included in Micronesia, and we believe they are not, the discovery of the Golden Cowry in the
Philippines is probably a range extension for this species. When Mr. Lahora sent the measurements of his first eight shells
to be registered in the Golden Cowry Register maintained at the Children's Museum, he mentioned, under the date February 5,
1962, that they were collected "in a period of more than a year between 1959 - 1960." Subsequently we learned that three
additional specimens had been taken, the one sent to Dr. Kay being No. 11. Except for No. 11 these shells were always found
in pairs. He spent an extra hour trying without success to find the mate of that one. All were taken at night, in
comparatively shallow water (not over 5 fathoms), "under ledges in the coral reef a little bit off the tidal zone." The
locality was the coastal town of Manay on the Pacific shore of Davao Province, southernmost Philippine Island of Mindanao.
This island lies about seven degrees north of the equator.
Mr. Lahora has kept a very close check on the Golden Cowries found in his province, and here is his report on that subject:
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