Multidentula squalina acutior ( Lindholm, 1922 )

Ruud, A. Bank, Henk P. M. G Menkhorst & Eike Neubert, 2016, Descriptions of new and little-known land snail taxa from Turkey, and establishment of a new genus (Gastropoda, Pulmonata: Lauriidae, Enidae and Vitrinidae), Basteria 80 (1), pp. 5-30 : 22-23

Multidentula squalina acutior ( Lindholm, 1922) ( Fig. 18 )

Chondrula acutior Lindholm, 1922b: 358 -359. Type locality: "Von mir im Genist des Fl. Tschoroch bei Kapandidi (unweit Batum) .... in einem tadellos erhaltenen leeren Stücke gefunden (coll. m.)". Holotype in ZIN ( Sysoev & Schileyko, 2009: 85, 259, fig. 38E).

Description. – Shell dextral, oval in outline, with a rather wide, open, slit-like umbilicus. The 6.5-7.7

whorls are rather convex with a rather deep suture. Teleoconch with irregular, oblique striae which are mostly rather fine; there are no spiral striae. Shell

solid, not or hardly translucent, rather dark brownish coloured, with a whitish band behind the peristome. The last whorl has an impression at the position of the infrapalatalis; the infrapalatalis and palatalis superior are visible outside as blurred white stripes. Peristome somewhat reflected, thickened by a prominent labial callus, the columellar and palatal insertion connected by a clearly visible callus (but the callus is mostly not extra thickened near the insertions). The subangularis is well developed and fused with the palatal peristome. The subangularis is connected to the parietalis by a more or less thickened callus. The very prominent parietalis is curved and deeply recessed. A spiralis is missing. Columellaris perpendicular to the columellar peristome, deeply recessed. Basalis present, well developed. Infrapalatalis and palatalis superior strongly developed; the infrapalatalis is the most prominent one. A suprapalatalis is also present, but is less prominent than the palatalis superior. A weak suturalis is available.

Measurements (n = 13). – H = 5.0-6.3 (mean 5.5); LWH = 2.6-3.1 (mean 2.9); MH = 1.7-2.1 (mean 1.8); LWD = 2.0-2.6 (mean 2.3); LWM = 2.3-2.9 (mean 2.6); MD = 1.5-1.8 (mean 1.6); NW = 6.5-7.7 (mean 7.0).

Localities. – Vilayet Artvin: crossing Artvin/Şavşat/Demirkent, 17 km towards Yusufeli, suspension bridge Çoruh Nehri (41.0925°N 41.8146°E) (NMBE/2); 5 km N. Erkinis (= castle N. Demirkent) (40.9258°N 41.7619°E) (HMT/1); N. Kınalıçam (= NNW. Cağliyan) (40.7567°N 41.6449°E) (HMT/41; NMBE 544678/1); Yusufeli (40.8215°N 41.5434°E) (HMT/3); 16 km SE. Yusufeli (40.7826°N 41.6967°E) (HMT/14); 17 km SE. Yusufeli, 5 km N. province boundary Erzurum/Artvin (40.7361°N 41.6651°E) (HMT/47). Vilayet Erzurum: 6 km SE. Çamlıyamaç (40.5854°N 41.5952°E) (HMT/81); Ispir, 38 km towards Yusufeli (40.6517°N 41.2299°E) (NMBE/4); deposition Tortum Gölü (40.6361°N 41.6312°E) (HMT/59); 9 km SW. Uzundere, 2 km S. exit to Dikmen (40.4698°N 41.5019°E) (HMT/117). Vilayet Gümüşhane: 6 km N. Arpalı (= 22 km NW. Bayburt) (40.5792°N 39.1334°E) (HMT/14); Salyazı, deposition Sulama Göletı (40.2446°N 39.8070°E) (HMT/29).

Differentiation. – Multidentula s. squalina ( Fig. 16 ) differs from M. s. acutior by the more densily packed and more pronounced oblique striae, the more pointed apex, the wider umbilicus, the mostly absent suturalis, the more reflected peristome, the less slen- der suprapalatalis, and the palatalis superior and infrapalatalis are generally more deeply situated in the aperture (i.e. they are situated further away from the peristome). Multidentula s. eudoxina ( Fig. 17 ) has a different dentition compared to M. s. acutior . The former lacks a suprapalatalis, the infrapalatalis is rather broad and seems slightly bifid, the palatalis superior is more prominent and the angularis is not fused with the palatal peristome, but instead connected to it by a thin callus.

Remarks. – The type locality "Kapandidi“ of acutior could not be traced. It is likely that Maradidi is meant, which is located in Georgia along the river Chorochi (= Çoruh Nehri) a few km north of the Turkish border (41.5030N 41.7123E).

An isolated locality from M. squalina has been reported by Fehér & Erőss (2009: 12, pl. 1 figs 8-10) from Albania. All other localities of M. squalina are restricted to Turkey (except one: the type locality of acutior ). The shells of Albania (as interpreted from the mentioned figures by Fehér & Erőss as well as those published by Welter-Schultes [2012: 194]) do not belong to the nominotypical subspecies, as the subangularis is not fused with the palatal peristome, the

presence of a suturalis, the oblique striae are less pronounced, the whorls are more convex, and the apex is less pointed. Furthermore, in M. s. squalina the basalis is shifted to a more subcolumellar position, and the infrapalatalis and palatalis superior are more deeply situated in the aperture. The Albanian subspecies differs from M. s. acutior by the less pronounced subangularis which is non-fused.

Another isolated locality of M. squalina is within Turkey itself, namely Çivril and Senirkent (both in the Göller Bölgesi area) ( Yıldırım & Schütt, 1997: 52, fig. 16; Schütt, 2001: 148, fig. c; Schütt, 2010: 146, fig. c). Unfortunately, the figures are too vague to determine its subspecific state.

Figures

Figs 16 - 20. Multidentula and Imparietula taxa from Turkey. 16, Multidentula squalina squalina (L. Pfeiffer, 1848), NMBE 548313 (H = 7.8 mm), Turkey, Vil. Karabük, eastern part Eskipazar, leg. Hausdorf, 27. ix. 1987. 17, Multidentula squalina eudoxina (Nägele, 1894), paralectotype SMF 14195 a coll. Kobelt ex Nägele (H = 6.3 mm), Turkey, Vil. Tokat, Tokat. 18, Multidentula squalina acutior (Lindholm, 1922), NMBE 544678 (H = 5.7 mm), Turkey, Vil. Artvin, N. Kınalıçam (= NNW. Cağliyan). 19, Multidentula reducta spec. nov., holotype NMBE 544681 (H = 6.2 mm), Turkey, Vil. Sivas, Zara, 16 km towards Imranlı. 20, Imparietula inflexa spec. nov., holotype NMBE 544683 (H = 12, 4 mm), Turkey, Vil. Giresun, 5 km N. Tamdere (= S. Yavuzkemal). All photographs Bochud & Neubert, × 8.