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01 Patella ulyssiponensis. Length 50.5mm. Kincardine, Scotland. August 1970.

Specimen at usual maximum shell-length for P. ulyssiponensis.

 

On this form, well-developed, thick, porcellaneous interior layers conceal outer shell so “marginal rays are never conspicuous” internally (Fretter and Graham, 1994), and features defined by differences of reflectivity resulting from differences in crystal-form of shell-material made by different parts of mantle are clearly visible.

 

1: aperture rim, minute (or absent) part of pigmented exterior shell-layer; secreted by mantle-edge.

2: wide peripheral “skirt layer” that reflects light, often iridescing blue, from many short crystalline lines parallel to rim; secreted by mantle-skirt.

3: narrower, matt, opaque, “pallial groove-band”; secreted by mantle roofing groove that contains the gills.

4: translucent, horseshoe-shape “pedal-retractor muscle scar”; mark left by muscle attachment.

5: very thin “anterior mantle-attachment scar” connecting ends of pedal-retractor scar; mark left by mantle attachment.

6: central “amphora area” enclosed by scars 4 & 5; secreted by mantle over visceral hump.

7: short mark across pallial groove-band where efferent pallial vessel enters nuchal cavity through gap in pallial gills.

8: excavated vertex patch; occurs more frequently in P. depressa than in P. ulyssiponensis, but, in this case, in the form of two adjoining elliptical pits. Cause unknown; but, as shape regular and consistent, damage by parasite/inquiline suspected. Similar pits on image Pu14 flic.kr/p/BpCkES .

 

SPECIES DESCRIPTION part A 2Pu flic.kr/p/BG8mKq

SPECIES DESCRIPTION part B 3Pu flic.kr/p/BRHsiR

Key id. features 4Pu flic.kr/p/BG8hhs

OTHER SPECIES ALBUMS

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Uploaded on December 5, 2015
Taken on November 24, 2015