Alan Solem

Sympatric species diversity of New Zealand land snails

Abstract Surveys for land snails of several bush patches on or near the Manukau Peninsula, southwest of Auckland, resulted in finding up to 60 species (only 3 introduced) in a single 4 ha patch of bush. Analysis of records from all bush patches suggests that an essentially sympatric community of about 72 native species is a probable reality, whereas in most areas of the world the sympatric existence of more than 15 land snail species is highly unusual. A first attempt at indicating the moisture, space, and foraging preferences of the 89 land snail species recorded from the Manukau Peninsula is presented, and an attempt is made to indicate broad categories of species association or habitat preference within this area. Many species occur throughout litter types (40–75% of all species in one bush patch would be in a 20 × 30 cm bag of litter from one spot), and it is hypothesised that the qualities of moisture retention and air space are more significant to the snails than the species of plant that provided t...

Maximum in the minimum: Biogeography of land snails from the Ningbing Ranges and jeremiah Hills, northeast Kimberley, Western Australia

Abstract The Ningbing Ranges and Jeremiah Hills are home to what is perhaps the greatest concentration of short range restricted e ndemic species found anywhere in the world. A radiation of more than 28 mainly allopatric species of camaenid land snails is packed into 52 km of limestone hills. The median linear range of a species is 1.65 km; the median area range is 0.825 km2. Located in the far northeastern tip of Western Australia between the east bank of the Ord River and the Northern Territory border, the Ningbing Ranges and Jeremiah Hills are Devonian limestone reef remnants, generally much less than 500 meters wide, that rarely reach 50–60 meters in height. The Ningbing Ranges have a length of 43.5 km; the Jeremiah Hills occupy a triangular area some 8.4 km on a side. Most of this remarkable diversity occurs within three restricted endemic genera of the pulmonate land snail family Camaenidae – Ningbingia Solem, 1981 with six species and one subspecies; Turgenirubulus Solem, 1981 with eight species; a...

New camaenid land snails from the northeast Kimberley, Western Australia

Abstract Seven new species and subspecies of camaenid land snails from northeastern Western Australia are described or discussed. The species all have very restricted ranges, and are found near the Northern Territory border in the area from both sides of the Cambridge Gulf in the north, to the hills lying southeast of Turkey Creek. The six described species and subspecies are: Amplirhagada cambridgensis from the Lyne River on the west side of Cambridge Gulf; Amplirhagada osmond’ from the Osmond Range-Palms Yard area southeast of Turkey Creek; Ordtrachia elegans from an isolated outlier of the Jeremiahi Hills northeast of Kununurra; Ningbingia australis elongata and Crisfilabrum rectum from the Ningbing Ranges north of Kununurra; and Mesodontrachia cockbumensis from the Cockburn Range southwest of Wyndham. Another probable new species of Cristilabrum from the Ningbing Ranges currently is represented by very limited material. It is not described at this time, but is illustrated for future-reference.

Pupilloid Land Snails from the South and Mid-west Coasts of Australia

Abstract Pupilloid land snails found in the areas between Kangaroo Island, South Australia and Albany, Western Australia, and then from the Chichester Range and Port Hedland in the Pilbara and North West Cape south to near Morawa, Western Australia are reviewed. Gastrocopta margaretae (Cox, 1868) ( + bannertonensis Gabriel, 1930 and complexa lredale, 1939) ranges from the Lower Murray River basin of Victoria and South Australia west to near Merredin and Albany, Western Australia; G. wallabyensis (Smith, 1894) is known from coastal and island localities in Western Australia from Point Quobba, north of Carnarvon south through Shark Bay and the Houtman Abrolhos to Green Head, just south of Eneabba; G. pilbarana, new species, has been collected from the Chichester Range near Roy Hill Station, the North West Cape, and places in the Shark Bay area (Salutation and Dirk Hartog Islands, Useless Bay); G. deserti Pilsbry, 1917, a species widely distributed in the Red Centre and barely reaching the south fringes of t...

Small land snails from Northern Australia, III: Species of Helicodiscidae and Charopidae

Abstract Two taxa of Indonesian origin and main distribution, the helicodiscid snail Stenopylis coarctata (Moellendorff, 1894) and the charopid Discocharopa aperta (Moellendorff, 1888), extend across northern Australia. They appear generally dispersed, reaching southern limits in the Napier Range and near Halls Creek, Western Australia; somewhat south of Alice Springs, Northern Territory; and then south to near Mackay, Queensland or into the north-eastern corner of New South Wales, respectively. Both species have been described several times. A second charopid, Pilsbrycharopa tumidus (Odhner, 1917), also is of New Guinea-Indonesian affinities. It has been recorded from a single collection on an island in the Fitzroy River on Noonkanbah Station, Western Australia. A third charopid, Dupucharopa millestriata (Smith, 1874) has been recorded once from Depuch Island, east of Roebourne, Western Australia. It has not been dissected, but shell features suggest that it also is of northern affinities. None of these ...

Small land snails from Northern Australia, I: Species of Gyliotrachela Tomlin, 1930 (Mollusca: Pulmonata, Vertiginidae)

Summary The small vertiginid land snail from Chillagoe Caves, Northern Queensland, Gyliotrachela australis (Odhner, 1917), is redescribed and refigured. Three new species, G. catherina from near Katherine, Northern Territory, G. ningbingia from the Ningbing Ranges north of Kununurra, Western Australia, and G. napierana from the Napier Range east of Derby, Western Australia, are described. The pattern of conchological variation in Gyliotrachela is discussed and the new taxa compared with extralimital forms.

Craterodiscus McMichael, 1959, A Camaenid Land Snail From Queensland

Summary Dissection of Craterodiscus pricei McMichael, 1959 shows that it cannot be classified in the Helicarionidae as originally suggested. It appears to be the most primitive species of the helicacean land snails yet dissected and is referred tentatively to the Camaenidae, s.l. Scanning electron micro-scope studies of the radula revealed that it has one of the most remarkable cusp structures found in a pulmonate snail.

Small land snails from Northern Australia, II: Species of Westracystis Iredale, 1939 (Mollusca: Pulmonata, Helicarionidae)

Summary Dissection of two small helicarionid land snail species from the Kimberley and near Katherine, Northern Territory show that the genus Westracyst is lredale, 1939 belongs to the subfamily Helicarioninae. One species, Westracystis lissus (E. A. Smith 1894) and its subjective synonym Westracystis tentus Iredale, 1939, is widely distributed in the Kimberley, with records from the Harding and Napier Ranges, north and east of Derby, respectively, to Kalumburu and then west to the Lawford and Laidlaw Ranges on th south-east fringes, finally across the border of the Northern Territory to the Sorby Hills and Keep River in the north with a single record along the Victoria Highway, 25 km east of Timber Creek Police Station. The second species, Westracystis fredaslini, new species, is known from the vicinity of Katherine south to Elsie Station on the Roper River, Northern Territory. Discussion of anatomical differences, aestivation strategies, annual growth differences, and ecology help to explain the wide di...

Cristilabrum kessneri, a new camaenid land snail from the Jeremiah Hills, Western Australia (Mollusca: Pulmonata: Camaenidae)

Abstract Cristilabrum kessneri, new species, is described from a small set of limestone hillocks on the eastern fringe of the Jeremiah Hills. They are situated 6.2 km west of Point Spring, Weaber Ranges and about 42 km north-northeast of Kununurra, Kimberley, Western Australia. C. kessneri has the most modified shell of any species belonging to the Ningbing Range-Jeremiah Hills camaenid land snail radiation. Its genitalia also has modifications that correlate with the small size of both the shell and the limestone hillocks on which it lives.