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Page 36 THE NAUTILUS, Vol. 122, No. 1
below), but the remainder of the shell is covered by very rosato (1917), who considered it as a separate species
narrow, raised lamella-like axial ridges and very thin spi- belonging to the Massotia group.
ral threads. Also its protoconch I sculpture is rather dis-
tinctive, showing a pattern similar to that observed in A. Alvania prusi could be confused with juvenile shells of
carinata, A. francescoi, A. rosariae, and A. tenera (as well Alvania lactea (the form with cancellate sculpture, see
as in many other rissoids), but having a coarser ornamen- Figure 49), which exhibit a very similar body whorl pro-
tation. file. Alvania prusi is quite close to A. fredianii Della
Bella and Scarponi (2000) from the Pliocene of Tuscany.
Alvania prusi (P. Fischer, 1877) Both species share the general shell shape and the finely
(Figures 50–52) reticulated sculpture, but the latter is of smaller size, has
a paucispiral protoconch, deeper sutures, and a weakly
Rissoa (Alvania) Prusi P. Fischer, 1877: 80. denticulated outer lip (see Della Bella and Scarponi,
2000: pls. 1 and 2).
Description: Shell small, sturdy, conical, partially
worn off, 4.7 mm in height, 3.2 mm in width. Protoconch Alvania rosariae new species
multispiral, conical, consisting of about little more than (Figures 62–79)
two convex whorls. Teleoconch is formed by about four
convex whorls, provided with a very delicate, cancellated Description: Shell small, sturdy, conical-ovate to tur-
sculpture almost giving a pitted shape to shell surface. riform, moderately to markedly inflated, reaching about
This sculpture consists of moderately pronounced spiral 5 mm in height, 3.5 mm in width (holotype 4 mm in
cords crossed by apparently flat axial ribs. Spiral cords height and 2.7 mm in width). Protoconch multispiral,
number 7–8 on penultimate whorl and 16 on body whorl; conical, consisting of about 2–2.1 convex whorls. Proto-
they are flatter and wider on shell base. Ribs, numbering conch I of about 0.8 whorls sculptured by 5–6 very fine
about 40 on penultimate whorl, are lacking in basal part spiral lirae irregularly interspersed with microscopic
of last whorl. Sutures slightly inclined and deeply im- granules. Protoconch/teleoconch transition well marked
pressed. Last whorl well-expanded, rather angulated at and sinuous adapically. Protoconch II sculptured by spi-
the base and inflated, comprising 3⁄4 of shell height. rally arranged microscopic pimples (stronger in adapical
Aperture wide, ovate to almost pyriforme, pointed adapi- portion) forming one to two spiral threads, the lower very
cally, comprising 1⁄2 of the total height, 2⁄3 of last whorl close to the suture, occurring on last whorl. Teleoconch
height. Outer lip prosocline, internally smooth, externally formed by about 4.2 usually very convex whorls, sculp-
with an almost flat, wide thickening, apparently smooth. tured by numerous axial ribs and slightly stronger spiral
Inner lip moderately arcuate, with a modest and narrow cords. The latter, rapidly increasing in count, number
reflection on columellar area, leaving a very small and 2–6, 6–10 (rarely 11), and 26–34 (in specimens higher
narrow umbilical chink (filled up with sediment). than 3.5 mm) on the first, penultimate, and last whorl of
the teleoconch, respectively. Some secondary, less
Type Locality: Isle of Rhodes marked cords may occur on last whorl, usually close to
the outer lip. The adapical one, two, and three spiral
Type Material: One syntype, R07495 in MNHN- cords on first, penultimate and body whorl, respectively
DHT, from type locality. are more pronounced. In specimens higher than 3.5 mm,
axial sculpture consists of 44–60 narrow ribs (52 in ho-
Material Examined: Eastern Mediterranean Sea, lotype) on the penultimate whorl. Ribs become narrower
Quaternary of Rhodes, type locality, MNHN-DHT and lamella-like to obsolete or lacking on shell base, par-
(R07495), 1 sh. ticularly close to columella. The same may occur on the
terminal portion of the body whorl (Figure 66). The in-
Habitat: It is very difficult to characterize the paleo- tersection of spiral cords with axial ribs gives a charac-
ecological significance of this extinct species since no teristic cancellate and gently nodular shape, forming a
data about its paleoenvironment are directly available or rectangular (almost equilateral in the central portion of
deducible. Furthermore, Fischer (1877) provided no the body whorl) pattern. The long axis of these rectangles
precise indication about the site, stratotype, and its sedi- is perpendicular to the shell axis on the central and
mentological and paleontological nature. Considering all abapical portion of whorls and parallel on upper part.
the other molluscan species described from Rhodes by Microsculpture consists of very fine, sometime irregu-
the same author, a shallow water depositional environ- larly interspersed, spiral lirae (Figure 77). These become
ment (linked to the modern phanerogam infralittoral obsolete on the penultimate and body whorls, where nu-
bottom) can be inferred. merous, very fine and narrow ribs (possible growth lines)
occur. Lirae are continuous only on adapical portion of
Distribution: The species is known only from the type early teleoconch whorls and never cover primary spiral
locality, and its distribution appears to be limited to the sculpture. Sutures slightly inclined and rather deeply
Quaternary of Rhodes. impressed. Last whorl well-developed, comprising about
2⁄3 to 4⁄5 of the shell height, usually with a very convex
Remarks: This taxon is practically unknown. To my profile. It sometime bears one or two close varices which
knowledge, the most recent treatment is that of Monte-
