Fissurellidae, Fleming, 1822

Key to species of Fissurellidae View in CoL found in the GB (see also Bogi & Giusti 1994 for differentiating Emarginula spp. )

1. Anterior part of the aperture with a deep slit reaching the edge ....................................................... 2

– Anterior part of the aperture entire, shell with a slit or a hole not reaching the edge ....................... 4

2. Shell height> half length, commarginal sculpture of tightly packed, vermiculate cordlets .............. ................................................................................ Emarginula christiaensi Piani, 1985 View in CoL ( Fig. 4I–J View Fig )

– Shell height ≤ half length, commarginal cords elevated and narrower than intervals ...................... 3

3. Apex definitely overhanging the posterior edge of the shell ........................................................................................................................................ Emarginula tuberculosa Libassi, 1859 View in CoL ( Fig. 4F–H View Fig )

– Apex not overhanging the posterior edge of the shell........................................................................ ......................................................................... Emarginula multistriata Jeffreys, 1882 View in CoL ( Fig. 4D–E View Fig )

4. Shell with a hole situated at the apex or close to it ........................................................................... 5

– Shell with a slit situated between the apex and the anterior edge .................................................. 10

5. Apex retaining coiled part with larval shell, and the hole immediately anterior to it ...................... 6

– Apex without coiled part, with the hole situated on it ...................................................................... 7

6. Shell height> shell length, shell surface smooth ............................................................................... ............................................... Profundisepta alicei (Dautzenberg & H. Fischer, 1897) View in CoL ( Fig. 6C–D View Fig )

– Shell height ≤ shell length, radial sculpture of granulose riblets ........................................................ ....................................................................... Profundisepta profundi (Jeffreys, 1877) View in CoL ( Fig. 6E–G View Fig )

7. Shell usually large, with a sculpture of radial and commarginal riblets ............................................. ..................................................................... Diodora tenuiclathrata ( Seguenza, 1863) View in CoL ( Fig. 4A–C View Fig )

– Shell always smaller than 10 mm with a sculpture of minute granules ............................................ 8

8. Granules arranged along radial lines ................ Fissurisepta granulosa Jeffreys, 1883 View in CoL ( Fig. 6A–B View Fig )

– Granules arranged quincuncially ...................................................................................................... 9

9. Shell height nearly twice shell length ................. Cornisepta rostrata ( Seguenza, 1863) View in CoL ( Fig. 6H–J View Fig )

– Shell height about the same as shell length ........................................................................................ ........................................ Cornisepta microphyma (Dautzenberg & H. Fischer, 1896) View in CoL ( Fig. 6K–M View Fig )

10. Shell sculpture formed by definite radial ribs intersecting commarginal cordlets ............................. ............................................................. Puncturella asturiana (P. Fischer, 1882) View in CoL [not found on GB]

– Shell sculpture formed by radial rows of granules, aligned to form ribs ........................................11

11. Apex strongly curved, overhanging posterior edge ............................................................................ ...................................................................... Puncturella granulata ( Seguenza, 1863) View in CoL ( Fig. 4K–L View Fig )

– Apex weakly curved, not overhanging posterior edge ....................................................................... .................................................................................... Puncturella agger Watson, 1883 View in CoL ( Fig. 5A–N View Fig )