greatest numbers close to the fort, although scattered individuals were seen elsewhere. The presence of T. pisana on only these south and south-west slopes, combined with the apparent suitability of parts of the north and east slopes suggests that its distribution here is restricted largely by aspect. Cowie (1982) showed that variation in vegetation cannot account for this restriction. There was little suitable habitat for T. pisana along the South Cliff, where the gardens of the houses on the cliff-top extend right to the edge. However, a few specimens and one or two small colonies were found, particularly between the public gardens beneath the Esplanade, and the edge of the cliff. The most extensive area inhabited by T. pisana in Tenby, and the area where its population density appeared highest (up to about 200 adults per sq m in summer Cowie 1982), was around the western end of the Esplanade and the sloping tarred path leading from it down to the beach. This included the areas Stubbs (1900) indicated as the 'Jubilee Gardens' and the 'Wreck Field'. ('Wreck' was presumably a mis- spelling of 'Rec', short for 'Rectory' the Rectory Field is now a metalled car park which retains this name.) The largest single part of this area inhabited by T. pisana is the bank between the Rectory Field car park and the sloping path to the beach, an area of about 30 x 8 m. The dominant plant of this bank is alexanders. T. pisana was also found in large numbers in patches alongside the path down to the beach, again associated largely with alexanders. From this centre its distribution extended inland around the edges of the car park, along Battery Road, and down the road to the 'Fundrome', which was demolished during the course of the survey. Fig. 2 Map of Stackpole Warren showing the area inhabited by T. pisana at present. Most of this area is now short turf. The paths and roads are metalled, and some of the paths have railings along their seaward sides. T. pisana was found stuck to these railings or in the uncut vegetation at their bases. Elsewhere it was found in the few areas of rough vegetation remaining, particularly behind the small amusement arcade and shop towards the bottom of the cliff near the beach. Further inland, a small colony (about 100 m2) was found on the seaward side of the railway bank at the bottom of the unsurfaced track leading from the inland end of Queen's Parade down to the golf club-house and Burrows. The vegetation was uncut, and the snails were associated largely with fennel (Foeniculum vulgare Mill.). The half of the Burrows nearer to Tenby was covered with sea buckthorn (Hippophae rhamnoides L.) and was devoid of T. pisana. A few individuals were found by the large rocky outcrop beside the railway about half way along the Burrows (no doubt the 'Black Rock' of Stubbs). A few were also found near the track which passes over the railway line, alongside this outcrop, and onto the Burrows. From here, T. pisana was found in small numbers scattered over the remaining south-western half of the Burrows, often associated with sea radish (Raphanus maritimus Sm.). This area does not carry sea buckthorn, the dominant plant being marram (Ammophila arenaria (L.) Link.). However, nowhere was a large area covered with vast numbers of T. pisana. Both sides of the Narberth Road were searched from where it joins the Norton (a road running Fig. 3 Detailed map of Tenby showing the present distribution of T. pisana.