09 Rissoa parva. shell height 2.6 mm. Menai Strait, Wales. September 2011.

09 Rissoa parva. shell height 2.6 mm. Menai Strait, Wales. September 2011.

1: labial varix and falciform mark not yet developed.
2: white costa.
3: brown lines in grooves between white costae.
4: brown lines traverse almost whole whorl from suture to basal spiral band without a break (varies).

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