Revision of the aperturally dentate Charopidae (Gastropoda: Stylommatophora) of southern Africa - genus Afrodonta s. lat., with description of five new genera, twelve new species and one new subspecies
Author
Herbert, David G.
urn:lsid:zoobank.org:author:0C09EE45-6198-482E-857A-EF690C2A016F
Department of Natural Sciences, National Museum Wales, Cathays Park, Cardiff, CF 10 3 NP, UK. Formerly at KwaZulu-Natal Museum, P. Bag 9070, Pietermaritzburg 3201, South Africa
phasianella@gmail.com
text
European Journal of Taxonomy
2020
2020-04-17
629
1
55
journal article
22877
10.5852/ejt.2020.629
3722aa65-b935-4294-ac20-0d1179da9015
3762280
ECEBD539-6E3E-45BE-A0CB-264DF3270CC0
Genus
Afrodonta
Melvill & Ponsonby, 1908
urn:lsid:zoobank.org:act:
4D5FE370-F963-46B2-9D66-0D999661727C
Afrodonta
Melvill & Ponsonby, 1908: 133
.
Type
species
Afrodonta bilamellaris
Melvill & Ponsonby, 1908
, by subsequent designation (
Burnup
1912
: 335
).
Diagnosis
Shell very small (max. diameter ±
1.8 mm
), discoidal to lenticular or almost subglobose; spire slightly to moderately raised; umbilical width narrow to moderate; whorl depth variable and whorls not conspicuously tightly coiled; periphery rounded to somewhat flat-sided, close to mid-whorl; last adult whorl sometimes descendant prior to aperture. Protoconch smooth or microscopically shagreened, with neither axial nor spiral sculpture, but sometimes with a slight subterminal swelling, comprising 0.67– 0.75 whorls beyond apical cap; teleoconch surface texture silky with a sculpture of simple, close-set, microscopic axial riblets of alternating strength, often with even finer spiral threads in their intervals. Aperture lunate; apertural dentition very variable.
Remarks
Afrodonta
comprises a relatively distinct group characterised by the almost smooth protoconch sculpture and silky teleoconch surface consisting of simple riblets of alternating strength. However, shell profile and apertural dentition exhibit considerable variation.
Some basic observations on the external anatomy and radula of the
type
species and of
Af.novemlamellaris
were provided by Godwin-Austen (in
Melvill & Ponsonby
1908
) and
Connolly (
1925
,
1939
), respectively. A peripodial groove is present, but a caudal gland is not evident. The radula formula is (6–7)+ (8–9)+1+(8–9)+(6–7), with tricuspid central and lateral teeth, and somewhat pectinate marginals. The jaw is composed of narrow plates set side-by-side (stegognathous). In
1925
, Connolly also described and illustrated the pallial anatomy of
Af. novemlamellaris
, noting that the ureter was reflected and included a secondary component running parallel to the rectum.
Solem (
1970
)
later commented that the presence of a secondary ureter and the configuration of the heart and kidney set
Afrodonta
apart from Pacific Island endodontids, which lack a secondary ureter.