Descriptions of New Species of the Diverse and Endemic Land Snail Amplirhagada Iredale, 1933 from Rainforest Patches across the Kimberley, Western Australia (Pulmonata: Camaenidae)
Author
Köhler, Frank
text
Records of the Australian Museum
2011
2011-11-30
63
2
167
202
http://dx.doi.org/10.3853/j.0067-1975.63.2011.1581
journal article
10.3853/j.0067-1975.63.2011.1581
2201-4349
5239547
1BCD4085-D2B9-400D-B504-8C85C30303D6
Amplirhagada epiphallica
n.sp.
Type
locality
.
Western Australia
,
NW Kimberley, N
side of
Prince Frederick Harbour
, near mouth,
16 km
W of Mt. Anderdon
,
0.3 km
from coast;
14°57'10"S
125°16'30"E
(
RFS 14-1
; coll.
V
. Kessner,
14 Jun 1987
) (
Fig. 1
)
.
Type material
.
Holotype
WAM
S34745
(preserved specimen) (Pl. 1.15;
Table 1
)
.
Paratypes
WAM
S34746
(3 preserved specimens)
,
FMNH 200539
(4 preserved specimens)
,
WAM
S34747
(2 dried shells)
,
FMNH 220541
(2 dried shells)
.
Etymology
. The species epithet refers to the presence of an epiphallus, which is a very distinctive feature among species of
Amplirhagada
.
Description
Shell
(Pl. 1.15;
Fig. 43 A–C
). Broadly conical with low spire, almost discoid. Thin to delicate, translucent. Periphery rounded to angulate; upper and basal sectors of whorls well rounded. Umbilicus 10–50% concealed by columellar reflection. Background colour pale yellowish brown; peripheral band well marked, moderately thick, brown, visible on most whorls; sub-sutural well marked to diffuse, moderately thick, visible on most whorls; outer and inner lip colour whitish. Protoconch
2.5 mm
in diameter, comprising about 1.2 whorls, essentially smooth. Teleoconch with regular axial growth lines; evenly distributed across shell surface. Angle of aperture about 45 degrees; outer lip thin, well rounded, expanded, not reflected; basal node absent or weakly developed. Parietal wall of inner lip inconspicuous. Average shell size 13.7±0.8 × 20.1±
0.7 mm
(
Table 1
).
Radular and jaw morphology
(
Fig. 43 D–F
). Tooth formula C + 13–14 + 4 + 18–20, with 150 rows of teeth 130 (n = 1). Jaw with 11 plates.
Figure 40.
Amplirhagada angustocauda
n.sp.
SEM of shell, radula and jaw (WAM
S34743
).
(A)
Protoconch and first teleoconch whorls viewed from above.
(B)
Detail of first teleoconch whorls viewed from above.
(C)
Close-up of sculpture on last whorl, lateral view.
(D)
Jaw.
(E)
Central and inner lateral teeth viewed from above.
(F)
Marginal teeth viewed from above. Scale bars:
A
, 200 µm;
B–C,
1 mm
D
, 100 µm;
E
, 20 µm;
F,
10 µm.
Genital morphology
(
Figs 44–45
). Penis complex elongated, tubular, coiled; actual penis extending proximal two thirds of penial complex. Inner penial wall completely lined with regular, fine pustulation arranged in corrugated pilasters; no main stimulatory pilaster differentiated. Penial sheath thick. Penial retractor muscle stubby, no longer than 1/10 of penial complex. Vas deferens moderately thick, entering penial sheath at apical end of penial complex, forming an extended loop, reflecting as an elongate, thin, tubular epiphallus, which gives rise to the short penis. Inner wall of epiphallus smooth, ciliated. Penial verge tiny, slender, forming a loop with pointed tip. Vas deferens elongated, winding before entering the uterus. Vagina long, tubular; inner vaginal wall and wall of bursa copulatrix with smooth longitudinal pilasters. Bursa copulatrix slightly extending base of spermoviduct, with bulbous head. Free oviduct elongated, coiled before entering the uterus, comprising more than half of length of anterior part of oviduct. Spermoviduct no longer than anterior part of oviduct. Albumen gland as long as spermoviduct.
Aestivation strategy
. Free sealer.
Figure 41. Genitalia of
Amplirhagada angustocauda
n.sp.
(WAM
S34743
). For labelling of structures see Fig. 3. Scale bar = 5 mm.
Figure 42. Penial anatomy of
Amplirhagada angustocauda
n.sp.
(WAM
S34743
). For labelling of structures see Fig. 4.
(A)
Interior anatomy of the penial wall.
(B)
Schematic view of the penis with the penial sheath being removed. Scale bars = 3 mm.
Remarks
. Anatomical description based on dissection of the
holotype
. Listed by Solem (1991) as “
Amplirhagada
NSP
35” and found in sympatry with
A. inusitata
n.sp.
and
A. pusilla
Solem, 1981
. The flat shell is similar to that of
A. discoidea
. However, the genital anatomy of this species is very unusual for
Amplirhagada
showing a combination of exclusive features, such as a very long and winding vas deferens, a long tubular vagina, very long tubular penis and vas deferens reflecting as an epiphallus within the strongly developed penial sheath, and a short, thin and coiled penial verge.