Conus (Chelyconus) praelongus (Hoernes & Auinger, 1879)

Descrizione e caratteristiche:

Die Schale des Conus praelongus ist sehr schlank, thurmformig, mit hohem Gewinde. Die einzelnen Umgangc desselben, sowie die Spira im Ganzen besitzen convexes Profil. Die ersten Umgange zeigen Spuren Ton Kornelung. Die Naht ist sehr schwach, der Umfang des Gehauses stark abgerundet. Auf dem ganzen Gehause, auch auf dem Gewinde, zeigen sich erhabene Querlinien, die mit feinen Parbenstreifen zusammen-fallen, und an der Basis der Schale starker entwickelt sind. Die Zuwachsstreifen sind schwach und verrathen oben einen massigen Ausschnitt der Miindung. Die Spindel ist wenig verdickt und gedreht, die Miindung schmal, unten wenig erweitert.

Die Parbenzeichnung des Conus praelongus besteht aus zahlreichen, dunkelbraunen Querlinien, die an einigen Exemplaren continuirlich sind, an anderen durch langliche Punkte gebildet werden⁽¹⁾.

Es liegen uns von dieser Form vier Exemplare vonLapugy vor, das grosste 41 Mm. lang, 18,5 Mm. breit, — alle zeigen die erwahnte Farbenzeichnung. Von Forchtenau werden in der Sammlun'g des k. k. Hof-Mineralien-Cabinetes gleichfalls vier Schalen autbewahrt, die jedoch insgesammt sehr schlecht erhalten sind und nur mit grosser Wahrscheinlichkeit dem Conus praelongus zugerechnet werden konnen. Zwei von diesen Forchtenauer Exemplaren haben grossere Dimensionen erlangt als die oben geschilderten vonLapugy; — eines misst 44 Mm. Hohe bei nahezu 19 Mm. Breite, ist also etwas schlanker; — ein noch grosseres Ge-hause mit beschadigter Spira mag bei 50 Mm. lang und 20 Mm. breit gewesen sein⁽¹⁾.

Conus praelongus stelit zwischen den eben geschilderten Varietaten des Conus Suessi und Formen aus dem iiicht weniger polymorphen Grebiete des Conus Vindobonensis Partsch⁽¹⁾.

The shell of the Conus praelongus is very slender, tower-shaped, with a high thread. The individual whorls of the same, as well as the spira as a whole, have a convex profile. The first whorls show traces of Kornelung clay. The seam is very weak, the circumference of the case is very rounded. Raised transverse lines, coinciding with fine streaks of colour, appear all over the case, including the threads, and are more developed at the base of the shell. The growth streaks are faint and reveal a massive section of the mouth at the top. The spindle is slightly thickened and twisted, the mouth is narrow and slightly widened at the bottom ⁽¹⁾.

The color markings of the Conus praelongus consist of numerous dark brown transverse lines, which are continuous in some specimens and are formed by elongated dots in others ⁽¹⁾.

We have four Lapugy specimens of this form, the largest 41 mm. long, 18,5mm. broad, — all show the color markings mentioned. From Forchtenau in the collection of the k. k. Hof-Mineralien-Cabinetes also preserved four bowls, which are overall very poorly preserved and can only be attributed to the Conus praelongus with great probability. Two of these Forchtenauer specimens have attained larger dimensions than those by Lapugy described above; — one measures 44 mm. High at nearly 19mm. width, so is slightly slimmer; - a still larger housing with damaged Spira may be at 50 mm. long and 20 mm. to have been wide ⁽¹⁾.

Conus praelongus stands between the varieties of Conus Suessi just described and forms from the not less polymorphic region of Conus Vindobonensis Partsch ⁽¹⁾.

Revised description ⁽²⁾.

Medium-sized olivoid shells; pointed apex with tuberculate early spire whorls; later spire whorls weakly convex to nearly flat, striate, forming a high, nearly straight-sided conical to weakly cyrtoconoid spire. Subsutural flexure shallow, moderately curved, moderately asymmetrical. Very indistinct shoulder coinciding with slight angulation and position of maximum diameter; last whorl moderately elongate, weakly ventricose, not constricted. Siphonal canal very short, moderately wide, straight; fasciole very weak and indistinct; few thin spiral threads on base. Colour pattern under UV light consisting of wide-spaced spirals of long dashes, intercalated by 1–2 weaker spirals of shorter dashes. If uppermost shell layer is eroded, these spirals are underlain by a dense pattern of spirals covering the entire shell.

Shell measurements and ratios. n = 11: largest specimen: SL: 44.9 mm, MD: 19.5 mm, mean SL: 33.7 mm (σ = 1.8), mean MD: 14.9 mm (σ = 2.6), spire angle: µ = 71.5° (σ = 3.1°), last whorl angle: µ = 33.8° (σ = 1.1°), LW: µ = 2.3 (σ = 0.1), RD: µ = 0.58 (σ = 0.03), PMD: µ = 0.87 (σ = 0.03), RSH: µ = 0.23 (σ = 0.03).

Discussion. The strong spiral pattern on the syntype illustrated by Hoernes & Auinger (1879) is somewhat misleading, as it represents a specimen with corroded uppermost shell layer. These spirals are just a colour pattern and do not represent a spiral sculpture as suggested by Halaváts (1884) and Strausz (1966). The stout, robust specimen with somewhat ventricose last whorl, illustrated by Atanacković (1969, 1985) as Conus praelongus , might represent another species. Lautoconus praelongus differs from the slightly similar Leporiconus suessi ( Hoernes & Auinger, 1879) , Leporiconus transsylvanicus ( Hoernes & Auinger, 1879) and Conus s.l.sturi Hoernes & Auinger, 1879 in its higher conical spire, shorter last whorl and lower position of the shoulder.