Page 13 - NAUTILUS_122-1_Garilli

V. Garilli, 2008 Page 31

Figures 38–43. Alvania francescoi new species, protoconch, teleoconch sculpture and microsculpture, lower Pleistocene of
Cartiera Mulino, SE Sicily, Ragusa, Vittoria. 38. Protoconch, paratype 2. 39. Protoconch, transition between protoconch I and II,
holotype. 40. protoconch I, holotype. 41. Sculpture of early teleoconch whorls, note how the spiral microsculpture becomes lacking,
paratype 2. 42. Microsculpture on the first whorl, paratype 2. 43. Detail of sculpture on the last whorl, note the numerous growth
lines, paratype 4. Scale bars: 200 ␮m in figures 41 and 43; 100 ␮m in figures 38–39; 50 ␮m in figures 40 and 42. Black and white
arrows indicate the protoconch I/protoconch II and protoconch/teleoconch boundaries, respectively.

height and 3.3 mm in width. Protoconch conical, consist- numerous, numbering up to eight and 16 respectively on
ing of about two convex whorls. Nucleus partially im- penultimate whorl. In early teleoconch whorls micro-
mersed. Protoconch I consisting of about 0.8 whorls, sculpture consists of fine, irregular, and discontinuous
sculptured by 5–7 spiral lirae and interspersed with nu- spiral threads formed by groups of small granules, not
merous closely packed granules, which are spirally and covering main spiral sculpture; remaining teleoconch
irregularly arranged. Protoconch II consisting of about with a finely reticulate ultrastructure covering all primary
1.2 whorls sculptured by pimples irregular in size and sculpture, formed by intersection of very narrow and
arrangement. Pimples are fused into short inclined lines raised lamella-like axial ridges and very thin spiral
(opisthocline and prosocline, Figures 53–54) or form one threads. Suture slightly inclined and deeply impressed.
to three discontinuous spiral ridges in abapical aspect of Body whorl well-expanded, comprising 3⁄4 of shell height.
whorl. Protoconch/teleoconch transition well-marked It may bear a varix, usually with angle of 180°; rarely a
and sinuous. Large shells consist of 4.2–5 weakly to double varix may occur, especially in slender and cancel-
rather convex whorls. These may be sculptured by a late shells. Aperture wide, ovate to almost pyriforme,
finely cancellate pattern formed by the intersection of rounded on its posterior aspect, narrowed anteriorly,
spiral cords and numerous delicate, narrow axial ribs, or comprising two thirds of last whorl height. Outer lip or-
by opisthocline, pronounced ribs. Ribs often start from thocline, internally smooth, externally thickened, mainly
early whorls and are crossed by finer spiral threads. In somewhat behind its edge, and covered by primary spiral
cancellate shells, cords and ribs are equal to subequal sculpture. Sometime, in ribbed morphs, the outer lip
and numbering up to nine and 40 respectively on pen- descends vertically, so that last whorl appears rather
ultimate whorl. In ribbed shells, cords and ribs are less cylindrical. Inner lip weakly arcuate, with a thin to rather

Figures 30–37. Alvania francescoi new species, holotype and two paratypes, lower Pleistocene of Cartiera Mulino, SE Sicily,
Ragusa, Vittoria. 30–32. Holotype, shell in apertural (30), profile (31) and dorsal (32) view. 33–35. Paratype 3, shell in apertural (33),
profile (34) and dorsal (35) view; 36–37. Paratype 4, apertural (36) and dorsal (37) view, the last showing a double varix on the last
whorl. Scale bars: 1 mm.