Caecum Fleming 1813
Creators: name: Vannozzi, Angelo
name: Pizzini, Mauro
name: Raines, Bret
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Caecidae
Caecum

description: Genus Caecum Fleming, 1813
Type species: Dentalium trachea Montagu, 1803 (by subsequent designation, Gray 1847: 203) from the Atlantic coasts of Europe, the Mediterranean Sea and northwestern Africa.
Key to South African Caecum species. The key applies to adult, well-preserved specimens. Periostracum characters are not taken into consideration.
1 Septum with mucro .................................................................................................2
– Septum without mucro..........................................................................................15
2 Mucro pointed, more or less central........................................................................3
– Mucro marginal.......................................................................................................4
3 Tube slender, tapering; septum narrow with flat ventral profile ................ chinense
– Aperture oblique; septum large with convex ventral profile................. lindae sp. n.
4 Macula large with a frosted appearance..................................................................5
– Macula small or absent............................................................................................7
5 Tube cylindrical, twisted, mucro clearly rotated toward the right side..................... ........................................................................................................... intortum sp. n.
– Tube subcylindrical, not or barely twisted ..............................................................6
6 Aperture strongly oblique, septum dome-shaped with an ear-like, right-oriented mucro............................................................................................ knysnaense sp. n.
– Aperture with a rather well­developed swelling, septum almost flat with a dorsal nail-like mucro ...................................................................... austrafricanum sp. n.
7 Aperture with a clear swelling ................................................................................8
– Aperture with a barely developed swelling or without it......................................10
8 Septum dome-shaped with dorsal mucro .............................................. cf. gulosum
– Septum on the cutting plane, mucro rotated toward the right side..........................9
9 Mucro broad, right-oriented............................................................... morgan sp. n.
– Mucro narrow................................................................................... cf. musorstomi
10 Tube small (length <2 mm)..................................................................................11
– Tube large (length> 2.5 mm)................................................................................14
11 Tube with microsculpture......................................................................................12
– Tube without microsculpture.................................................................................13
12 Tube evenly arched, aperture simple, microsculpture composed of incised collabral grooves ............................................................................................... incisum sp. n.
– Tube slender, microsculpture composed of longitudinal worm-like incisions.......... ............................................................................................................. maraisi sp. n.
13 Septum subquadrate in lateral view, mucro right-oriented ............... subquadratum
– Septum dome-shaped with a rounded, almost dorsal mucro.................. inhacaense
14 Tube colourless, semitransparent, with several small rings, more visible in the abapical half of the tube ......................................................................... leilae sp. n.
– Tube whitish, opaque, with some strong rings before aperture; microsculpture composed of several wavy longitudinal threads ............................ neocaledonicum
15 Sculpture formed by strong, well­defined rings....................................................16
– Scupture weak or absent........................................................................................17
16 Sculpture formed by 20–25 strong rings, septum flat on the cutting plane............... ............................................................................................................... sepimentum
– Sculpture formed by smaller and more numerous rings, often missing in central portion of tube ...................................................................................... cf. oahuense
17 Tube smooth with some rings before aperture ........................................ succineum
– Tube smooth without sculpture or microsculpture................................. cf. glabrum
description: Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on pages 100-101, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/7661863