ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 59. PARS ZOOLOGICA 1967.

A Revision of the 0. F. Müller, 1774, in (, Basommatophora)

By L. PINTÉR, Budapest

There is nothing much said about the genus Carychium in Hungarian malacological literature. The various authors had not deemed it worth while to discuss it at length, because the sole Hungarian species belonging to it, minimum O.F. MÜLLER, 1774, seemed to be rather uniform and hardly liable to vary. True, a variation, ssp. tridentatum (Risso,) 1826, has long been listed in our fauna, but the difficulties involved in its separation, and the highly relative value of the identification, were not worth the trouble. Perhaps this very relativeness gave birth to the mistrust in treating (Risso) —a distinct and "good species" in foreign literature since long decades — as a taxon anything more than of a subspeeifie rank in our home publications. According to the traditional means of identification, the most characteristical features of the two species (or subspecies) are the proportion of the total height (Hx) and width (W), and the total height (Hj) and apertural height (H2) respectively. Literature carries, in general, the following figures :

Carychium minimum O. F. MÜLL. HX:W = 1.6 — 2 : 1

Hi:H2 = 2.3-2.55 : 1

Carychium tridentatum (Risso) H1:W = 2.1 — 2.4 : 1

Hx:H2 = 2.55-3 : 1 In this respect, the data of the authors rather agree with each other. Accordingly, the investigated specimen is to be regarded as Carychium minimum in which the proportion (Px) of H, and W does not exceed 2, and that of P2 ^HjiHj) is below 2.55. The figures for Carychium tridentatum are above 2.1 and 2.55 respectively. Theoretically, the difficulty would lie in the actual existence of the proportion be­ tween 2 and 2.1. Whoever has actually tried, even once, to separate the two species, will know from his own experience that the majority of identifications are insecure owing to an overlap, in most of the cases, of the proportions. In essence, there will always remain in any given population a rather high per cent of individuals which might be relegated, on the basis of the two kinds of proportions, to any one of the two groups. WATSON and VERDCOURT (1953) published a paper on the occurrence of Carychium species in Great Britain. After a thorough study, the two authors have shown that, for a taxonomic separation of the species belonging to the genus Carychium, there is but one reliable specific feature, namely the shape and position of the parietal lamella (Figs. 1, 2). This feature proved to be of such constancy that, on its basis, the specific distinctness of Carychium tridentatum (Risso) can be established with complete certainty. The Figure clearly illustrates the difference between the two species. If the penul­ timate whorl over the aperture is carefully removed, the parietal lamella, extending up­ wards, will become easily discernible. In the case of Carychium minimum O. F. MÜLLER, the configuration of the lamella resembles an obtusely pointed acute angle of uniformly arcuate sides toward the aperture, whereas, in Carychium tridentatum (Risso), it tends initially horizontally, indeed, frequently upwards, and then sweeps steeply and almost perpendicularly downwards, away from the columella and towards the inside of the shell. It is further characteristic of C. tridentatum that the parietal lamella, at the point indi­ cated by an arrow in the Figure, forms an exclinate and expanding rim in most of the cases, a feature entirely lacking in C. minimum. Following the findings of WATSON and VERDCOTJRT, the revision of the earlier data had been made in a number of European countries (as also in Hungary, but our material was destroyed in 1956). By its thoroughness, Dr. V. LOZEK'S (1957) checking of the Chechoslovakian Carychium material excels above all others. After such preliminaries, I have reexamined, in August 1966, the Carychium material

Fig. 1. Carychium minimum MÜLL. — Fig. 2. Carychium tridentatum (Risso). deposited in the Hungarian Natural History Museum, and then endeavoured to gather all available materials in the possession of Hungarian malacologists for further checking and separation into species. The material totalled 16.597 shells, largely from all regions of the country. However, as will be seen from the list of localities, the present paper can only be preliminary to an even more general revision, pending ultimately on a planned faunistical exploration of the country in this respect. It is my agreeable duty to express my gratitude to all who had collected the material in question, and cordially permitted its study. Thus, first of all, to my father, Dr. I. PINTÉR, my master and main support in malacological investigations. Dr. P. AGÓCSY made available the entire mollusk collection of the Hungarian Natural History Museum which thus became the starting point of the entire revisional work. Dr. A. GEBHARDT, I. VÁSÁRHELYI, Á . KÁROLYI, Dr. J. PAPP, Dr. GY. KOVÁCS, Dr. A. RICHNOVSZKY, Dr. E. KROLOPP, I. SAJÓ, Dr. L. VÖRÖSS, and Dr. M. WIESINGER, had all sent me their Carychium materials — thanks are due to them all. I have to say especial thanks to Dr. V. LOZEK, who was the first to call my attention to the Carychium-jn ohlem and thus was the mainspring of the entire project. I had several aims in studying Carychium specimens from Hungary. I was first of all interested in the exact and secure separation of the two species, Carychium minimum and C. tridentatum. Further, I intended to establish the distribution of the two taxa, and thus correct or complete literature data, insofar as permitted by the available material. Finally, I wanted to obtain informations whether there be discernible or eventually inter­ prétable differences between the major populations, and in how far measurement data given in literature correspond to actual examinations.

I. Carychium minimum or tridentatum?

This question has already been answered by the above discussion. The shape of the parietal lamella will decide specific relegation with complete certainty even for specimens doubtfully identified on the basis of other characteristics. I have examined the parietal lamella of many thousands of exemplars, and every specimen had justified the correctness of WATSON'S and VERDCOURT'S statements. Though, together with the general shape of the shell, the parietal lamella is also subject to certain individual variations, I have never found a lamella transitional between the two species. Indeed, in the great majority of cases, the difference is so sharp between the two forms that a safe indentification can be rendered even after the first glance at it.

II. The distribution of the Carychium species in Hungary

According to Soós (1957) Carychium minimum is generally distributed in the Great Plains and the Transdanubia, whereas Carychium tridentatum is known only from some few localities, namely Magyaregregy, Abaliget (Mts. Mecsek), and the Cuha valley (Mts. Bakony). According to other data, Dr. J. VÁGVÖLGYI (1948) collected it in the Mts. Börzsöny, while Dr. I. PINTÉR (1960) published some further sites from the Mts. Bakony, concurrently pointing out the need for a complete revision of the Carychium-coïnplex. On the basis of my examinations, I submit a tabulation of the known localities of occurrence in Hungary of the two species. The country is subdivided therein into physiogeographic units, though this fails to render a wholly correct picture of actual conditions. 1. Hungarian localities of Carychium minimum Müll.

Bakony (Bakonybél, Hódoséi* vgy., Kislőd, Magyarpolány, Noszlop), Balatonaka- rattya, Balatonberény, Balatonederics, Balaton fenyves, Balatonhídvég, Balatonmagya- ród, Balatonmáriafürdő, Balatonszentgyörgy, Budai hegység (Hárshegy, Hűvösvölgy), Csurgó, Dombóvár, Drávasztára, Esztergom, Fenékpuszta, Garé, Gyenesdiás, Hévíz, Homokkomárom, Kapospula. Kardosfa, Kilimán, Kisbalaton, Korpavár, Kovácsi hegy, Kustány, Lasztonya, Lázhegy, Leányfalu, Mecsek (Abaliget, Bédai erdő, Hidasi vgy., Magyaregregy, Mélyvölgy, Síngödör völgy, Szuadó vgy., Takonyé völgy), Nagyárpád, Nagyberek, Nagykanizsa, Ortilos, Palkonya, Pellérd, Pécs, Pécsújhely, Pécsvárad, Pilis (Búbánat völgy, Diósvölgy, Hoffmann-kút, Malom völgy, Szőkeforrás), Rezi, Sopron, Sormás, Sumony, Szentgyörgyvár, Szigliget, Tokaj puszta, Uzsa, Vállus, Várvölgy, Vértes (Pusztavám, Tata), Vonyarcvashegy, Vörs, Zalaapáti, Zalalövő, Zákány. Baja, Bátor­ liget, Békéscsaba, Császártöltés, Gyula, Jászfelsőszentgyörgy, Kelebia, Ocsa, Petneháza, Szigetújfalu, Tákos. Mátra (Hasznosi patak, Mátrakeresztes, Parádfürdő), Bükk (Alsó­ sebesvíz, Alsózsolca, Arló, Diósgyőr, Felsősebesvíz, Garadna völgy, Hámori tó, Hejő- csaba, Lillafüred, Nagytekenyős, Sólyomkút, Szalajka völgy, Szarvaskő, Szárazvölgy, Szinva-hordalék, Vadászvölgy). Duna-hordalék (Budapest, Dömös, Esztergom, Pilis­ marót). Tisza-hordalék (Szeged, Telektanya, Újszeged).

2. Hungarian localities of Carychium tridentatum (Risso)

Bakony (Bakonybél, Bocskorhegy, Cuha, Hódosér völgye, Kőárok, Kőrishegy, Né­ metbánya, Noszlop, Ördögvölgy, Veszprém), Balatonfenyves, Balatongyörök, Budai hegység, Cserszegtomaj, Drávasztára, Esztergom, Gyenesdiás, Hévíz, Homokkomárom, Kardosfa, Kilimán, Korpavár, Kovácsi hegy, Lasztonya, Mecsek (Abaliget, Kantavári völgy, Márévári völgy, Mély völgy, Síngödör völgy, Szuadó völgy), Nagykanizsa, Ór tilos, Pilis (Bitóéi völgy, Cserepes völgy, Fekete hegy, Hoffmann-kút, Holop kút, Keserűs patak, Körtvélyes, Malom-völgy, Salabasinai kút, Szőkeforrás, Tündérszakadék), Rezi, Sopron, Tokaj puszta, Vállus, Várvölgy, Vértes (Oroszlány, Tata), Vonyarcvashegy, Bátorliget, Békéscsaba, Császártöltés, Jászfelsőszentgyörgy, Szigetújfalu, Tákos. Bör­ zsöny (Csóványos, Kemenes patak, Tűköves forrás), Bükk (Ablakoskő, Alsósebesvíz, Arló, Buzgókő, Demény-patak, Felsősebesvíz, Garadna völgy, Gyertyánvölgy, Harica patak, Hámori tó, Háromkúti völgy, Hosszúvölgy, Hórvölgy, Köpüsi szikla, Köpüsréti forrás, Létrási barlang, Lillafüred, Mélyvölgy, Ómassa, Savósi völgy, Szarbalápa, Szarvaskő, Szárazvölgy, Szilvásvárad, Szinva-hordalék, Szögliget, Tekenősyölgy, Vadászvölgy). Duna-hordalék (Esztergom). Tisza-hordalék (Szeged, Telektanya, Újszeged). Glossary of Hungarian terms: barlang = cave ; erdő = forest; forrás = spring; hegy = = mountain, hill; hegység = mountains, range; hordalék = stream deposit, drift; kút = well hole; patak = brook; szikla = cliff ; tó = lake; völgy — valley. As is to be seen from the list, we have hardly any data from the Grest Plains, though collectings must have been made also in this area. Data are entirely absent from the Zemplén range and the Mts. Gerecse; the Mts. Mátra, the Buda hills and the Mts. Vértes are also poorly represented. However, the available material allows to state (corroborating the results of investigations abroad) that Carychium minimum is primarily characteristic of the plains, but it occurs also in the valleys of the hilly and mountainous chains. It is highly hydrophilous, hiding under wet logs and in mosses. On the other hand, Carychium tridentatum is bound preponderantly to hilly and mountainous regions. It occurs, as far as our experiences go, only exceptionally in the plains though this statement may suffer strong modifications after a reexamination of specimens origi­ nating from the Great Plains. This species, too, favours wet sites, though it can be collected also in shaded yet dry rocky ledges. In a great number of localities (in 35.5 per cent of the examined material), it occurs together with Carychium minimum. In all likelihood, none of the localities of C. tridentatum can be regarded as pri­ mary habitats in the Plains. The strikingly abundant population of the Dajka-kert in Békéscsaba is hardly interprétable were it not regarded as an introduced element : the species might have arrived here either with waterborn drift in earlier centuries or by the means of plants. In any case, it is today extremely vigorous. The finding in Jászfelsőszentgyörgy derives obviously from the deposits of the river Zagyva, Tákos lies in the inundation area of the Tisza, and the 79 specimens found near Szigetújfalu on the island Csepel also refer to a waterborn origin. On the other hand, it would require first-hand investigations in situ to find an adequate explanation for the occurrence of C. tridentatum in Bátorliget and Császártöltés. Based on our experiences hitherto, it may safely be stated that neither one of the species show any special requirement as to soil or rock substrate. They might equally be found in weakly acidic surroundings (Feketehegy, Mts. Pilis; pH 6—6.8), as in neutral or weakly basic habitats (Malom valley, Pilismarót; pH 7 — 7.5). They have been collected on basalt, andésite, limestone and dolomite; they live in com­ pact, clayey soils and can be found also in locust woods on sand. However, indi­ vidual density is indubitably the greatest in calciferous habitats, e.g. the Garadna valley in the Mts. Bükk. Though the major part of the collections derive from the drift of the Garadna brook, it is still striking that the Carychium shells found here constitute 38 per cent of all examined materials in Hungary. Something should also be said of the drift materials of the Danube and the Tisza. The Carychium materials collected in the drift of the two rivers are tabulated as follows: Table 1 Duna-drift Tisza-drift C. minimum 724 spec. 99.59% 174 spec. 47.7% C. tridentatum 3 spec. 0.41% 191 spec. 52.3% Total 727 spec. 100% 365 spec. 100%

These data are of course unreal. In evaluation, one must consider the number of collectings, their intensity, and the geographical situation of the given locality. Comparing the materials deriving from Telektanya (Upper Tisza) and Szeged (Lower Tisza), the numerical proportion of the two species increases toward the south in favour of C. minimum, whereas in the north, in the vicinity of the mountains, it is C. tridentatum which plays the leading role. With respect to the Danube, collectings had been conducted within a relatively short stretch (Esztergom—Budapest; about 05 km). Though the Danube flows among mountains in northern Hungary, and though Carychium tridentatum thrives abundantly in the tributaries of the river Ipoly which, together with the river Garam, carry their waterborn material also from the Car­ pathians, the per cent occurrence of C. tridentatum is still so low along the Eszter­ gom—Budapest reach of the Danube that we are at the moment at a loss to account for it. For this very reason it were most gratifying to conduct investigations of the drift, involving the entire length of our streams, to obtain some satisfactory answer concerning the actual origin of the drift species. It is worthy of note, also here, that the origin of Argna species ( = Agardhia), Acicula ( = Acme) perpusilla? (REINH.) (Tisza-drift), and a still unpublished recent Paladilhia species (Esztergom, Danube- drift), is entirely unclarified, though these problems touch heavily on our zoogeo- graphical knowledge.

III. Population analysis

In the course of separating the two species, it was found that the variability of these taxa is considerably bigger than given in literature. This refers in general to dimensions, or, to be more exact, the ratios of the measurements. To place the matter into a sharper focus, I have selected for our study purposes the biggest material — containing therefore the greatest number of individual aberrations (Garadna valley, Mts. Bükk, 27 Febr., 1951, leg. I. VÁSÁRHELYI). This collecting resulted in 2691 Carychium specimens. Of this rich material, I took a random sample of 200 adult shells and removed with a sharp pin the partion of the penul­ timate whorl above the aperture to free the parietal lamella, The material was then separated into the two species, to wit: 43 specimens of C. minimum (21.5%) and 157 specimens of C. tridentatum (78.5%). I have then taken 20 specimens of each species and measured, with a hundredth millimeter exactness, the total height, width, and aperture height of all specimens, and then calculated from the values received the proportions of the two ratios (Table 2). Prior to evaluating the results of the investigation, I also submit the data of a population originating from an entirely different region of the country (valley of the Malom brook, Pilismarót, 8 July, 1965, leg. L. PINTÉR). This collection resulted in 252 Carychium specimens. The method of examination was in essence identical with the preceding one (Table 3). Since, in both cases the number of measured specimens were rather small, the data cannot be regarded as completely definitive. There occur presumably smaller and bigger specimens than the examined ones in the populations under discussion, but even this less than wholly satisfactory solution will suffice for our purpose. By separately summing up the numerical values and ratios, and then dividing them with the number of specimens, the means of the two populations were obtained (Table 4). Table 2

Collection data:

Mts. Bükk: Oaradna- völgy 27. 2. 1951 Leg. : I. Vásárhelyi

H P H W 2 P l l 2 1 Carychium minimum Müll.

1. 73 0. 92 0. 73 1. 88 2. 37 1. 72 0. 90 0. 81 1. 90 2. 12 1. 81 0. 95 0. 77 1. 91 2. 35 1. 84 0. 96 0. 74 1. 91. 2. 49 1. 90 0. 96 0. 89 1. 97 2. 14 1. 73 0. 87 0. 64 1. 99 2. 70 1. 76 0. 88 0. 68 2. 00 2. 59 1. 77 0. 89 0. 76 2. 00 2. 33 2. 03 1. 00 0. 76 2. 03 2. 67 1. 88 0, 92 0. 80 2. 04 2. 35 1. 97 0. 96 0. 81 2. 05 2. 43 2. 05 1. 00 0. 88 2. 05 2. 33 1. 95 0. 95 0. 90 2.06 2. 17 1. 82 0. 88 0. 64 2. 07 2. 84 1. 84 0. 88 0. 71 2.09 2. 59 1. 98 0. 94 0. 88 2. 10 2. 25 2. 21 1. 05 0. 88 2. 10 2. 51 2. 20 1. 04 0. 80 2. 12 2. 75 2. 08 0, 94 0. 72 2.21 2. 89 1. 88 0. 80 0. 76 2. 35 2. 48

Carychium tridentatum Risso

2. 02 0. 90 0. 73 2. 24 2. 76 2. 21 0. 98 0. 80 2.24 2. 77 2, 00 0. 88 0. 73 2.27 2. 74 2. 18 0. 96 0. 69 2. 27 3. 16 1. 76 0. 77 0.66 2. 28 2. 67 1. 65 0. 72 0. 52 2.29 3. 18 1. 76 0. 76 0. 64 2. 32 2. 75 2. 08 0. 88 0. 63 2. 36 3. 28 1. 74 0. 73 0. 56 2. 38 3. 10 2. 16 0. 90 0. 72 2. 40 3. 00 1. 89 0. 77 0. 78 2. 46 2. 42 2. 10 0. 85 0. 72 2. 47 2. 92 2. 26 0. 90 0. 74 2. 51 3. 06 2. 12 0. 84 0. 64 2. 52 3. 31 2. 31 0. 92 0. 72 2. 52 3. 21 1. 98 0. 75 0. 61 2. 64 3. 25 2. 16 0. 80 0. 67 2. 70 3. 21 2. 07 0. 76 0. 60 2. 72 3. 45 2. 08 0. 75 0. 63 2. 77 3. 28 2. 00 0. 71 0. 56 2. 81 3. 57 Table 3

Collection data

Pilismarót : Malom patak völgye 8. 7. 1965 Leg. L. Pintér

H W H P p l 2 l 2

Carychium minimum Müll.

1. 77 0. 88 0. 72 1. 83 2.45 1. 74 0. 93 0. 73 1.87 2. 38 1. 75 0. 93 0. 77 1. 87 2. 26 1. 78 0. 93 0. 73 1.91 2. 45 1. 79 0. 94 0. 78 1.91 2. 31 1. 79 0. 94 0. 81 1.91 2. 20 1. 80 0. 93 0. 77 1. 93 2. 34 1.81 0. 93 0. 76 1. 95 2. 37 1. 86 0. 93 Ö. 73 2. 00 •2. 55 1. 86 0. 93 0. 81 2. 00 2. 30 1.86 0. 93 0. 89 2. 00 2.. 09 1. 87 0. 94 0. 72 2. 00 2. 42 1. 95 0. 98 0. 81 2. 00 2. 40 1. 73 0. 84 0. 71 2. 05 2. 45 1. 80 0. 88 0. 72 2. 05 2. 50 2. 00 0. 97 0. 73 2. 06 2. 60 1. 69 0. 80 0. 76 2. 10 2. 21 1. 83 0. 87 0. 77 2. 10 2. 37 1. 98 0. 89 0. 73 2. 22 2. 72 2. 10 0. 93 0. 81 2. 26 2. 60

Carychium tridentatum Risso

1. 86 0. 89 0. 77 2. 09 2. 42 1. 63 0. 78 0. 65 2. 10 2. 50 1. 70 0. 81 0. 73 2. 10 2. 33 1. 70 0. 81 0. 73 2. 10 2. 33 1. 78 0. 85 0. 75 2. 10 2. 37 1. 58 0. 73 0. 65 2. 16 2. 44 1. 75 0. 80 0. 66 2.17 2. 64 1.78 0. 81 0. 69 2. 20 2. 59 1. 79 0. 81 0. 65 2.20 2. 75 1. 72 0. 78 0. 61 2. 21 2. 80 1. 77 0. 79 0. 64 2. 25 2. 75 1. 84 0. 82 0. 63 2. 25 2. 90 1. 70 0, 75 0. 73 2. 26 2. 33 1. 86 0. 81 0. 65 2. 30 2. 87 2. 00 0. 86 0. 65 2. 33 3. 06 1. 81 0. 76 0. 64 2. 37 2. 81 1. 95 0. 81 0. 73 2. 40 2. 66 1. 85 0. 76 0. 68 2. 42 2. 70 1. 79 0. 73 0. 57 2. 45 3. 14 1. 99 0. 81 0. 69 2. 45 2. 88 Table 4

Carychium minimum 0. F. MÜLL. Carychium tridentatum (Risso)

Garadna valley Pilismarót Garadna valley Pilismarót

Hi 1.90 1.84 2.03 1.79

H2 0.77 0.76 0.07 0.08 W 0.93 0.92 0.83 0.80 Pi 1.94 2.00 2.45 2.25 2.46 2.40 3.05 2.71 P2

Actual extreme values

P-T 1.72-2.21 1.69-2.10 1.05-2.31 1.58-2.00 H, 0.64-0.90 0.71-0.89 0.52-0.80 0.57-0.77 W 0.80-1.05 0.80-0.98 0.72-0.98 0.73-0.89 Pi 1.88-2.35 1.83-2.20 2.24—2.81 2.09-2.45 2.12-2.89 2.09-2.72 2.42-3.57 2.33-3.14 P2

IV. Conclusions 1. Actual variation within the two Carychium species is considerably higher than indicated by literature data hitherto. 2. Carychium tridentatum varies within wider limits than C. minimum. 3. No safe identification can be given solely on the basis of measurement ratios, since, according to the two populations, the two ratios overlap one another by 25—38 per cent:

1.83 — 2.35 (C. minimum,) 2.09 — 2.81 (G. tridentatum)

P2 2.09 — 2.89 (C. minimum) 2.33 — 3.57 (C. tridentatum)

4. The variation of the Pilismarót population is narrower than that of the Bükk material: the data of the two species are leveling out, hence a correct identification can hardly be given without recourse to a dissection of the shell. 5. Despite the indicated differences, no varieties in the taxonomic sense can be given, owing to the occurrence of transitions in all materials. Neither are different ecological conditions decisive, since, for instance, the populations deriving from the Mts. Mecsek (limestone) and the Mts. Keszthely (dolomite) gave measurement data nearly identical with those of the Pilismarót population (andésite), besides which the Bükk forms can be found intermixed with the others.

Summary The present paper submits a survey of the distribution of two species (Carychium minimum 0. F. MÜLLER, and C. tridentatum Risso) in Hungary, the possibilities of separation and identification, as well as the rate of individual and population variabi- lity. The study began as a revision of the mollusk material in the Hungarian Natural History Museum, and then expanded to a nationwide survey.

References: LOZEK, V.: Ceskoslovenské druhy rodu Carychium Müller (Acta Soc. Zool. Bohem., 21, 1957, p. 3). — PINTÉR, I. : Adatok a Dunántúl egyes tájainak Mollusca- faunájához (Allatt.,Közlem., 47, 1960, p. 135). — Soós, L. : Mollusca — Puhatestűek (in Magyarország Állatvilága, 19, 1957, p. 2/45 — 46). — Szijj, J. & VAGVÖLGYI, J. : Contributions to the MoUuscan Fauna of the Börzsöny Mts. (Fragm. Faun. Hung., 11, 2, 1948, p. 33 — 36). — VAGVÖLGYI, J. : Malacofaunistical Data (Ann. Hist.-nat. Mus. Nat. Hung., Ser. nova 7, 1956, p. 451 — 453). — WATSON, H. & VERDCOURT, B.: The two British species of Carychium (Journ. of Conch., 23, 1953, p. 306 — 324).