Gyroscala rupicola (brown-banded wentletrap) is uncommon on Long Island, almost all specimens found since the 1970s were in Great South Bay, on the south shore of Suffolk County. At times (especially in late Spring) it was possible to find anywhere from a few to several hundred at a single site at 1 low tide; since about 2012 this species has sharply declined in numbers, probably due to several environmental changes affecting Great South Bay, such as increases in salinity (resulting from the breach of Fire Island, the outer boundary of Great South Bay, by hurricane Sandy in 2012) and/or increasing seaweed blooms- including at least one introduced species, resulting from increased discharge of nitrogen from suburban development and landscaping etc ...similar changes have been observed in the population of other snails, such as Crepidula convexa which used to wash up by the 100s to 1000s, yet now only numbers a few dozen at a time.

This 22mm fresh dead shell is the 1st rupicola I have found along Great South Bay in about 2 years, and similarly low numbers are now the norm here, so for now this is a 'record' specimen that they still appear to be hanging on but in apparently low numbers.

(photography by Doyeon Kim)

Three of the best color variations from among the 50-60 paired scallops found on the beach on either side of the ferry slip for the Shelter Island (south) ferry at North Haven with Harry Zirlin today. (These were all from the west side).

Apologies for the blurry photo, this shell is about 6mm long and did not photograph well with a smartphone.

Found in beach drift to the east of the Shelter Island (south) ferry slip at North Haven.

At the time of the publication of the book

Seashells of Long Island, New York - A Guide to Their Identification and Local Status,
published by The Long Island Shell Club, Inc.,, 1988

this tiny species was described therein as one of the rarest shells from Long Island, with only one recently found specimen (from the same location). As older records note, it can be found around Long Island, I'm up to about 24 local specimens from Nassau and Suffolk Counties now. The bright color of fresh shells, like this one, makes them a bit easier to spot in drift, but I am sure some are overlooked due to their diminutive size.