STUBBS : LAND AND FRESHWATER SHELLS OF TENBY. 363 



on the water-wheel of the old mill near Scotsburgh, and under stones 

 in the bed of the stream. A rather curious habitat is the sea-cliff at 

 Waterwynch ; it lives on the ledges of the rock near high-water mark. 

 Although fresh water trickles over them from the cliffs above, they 

 must get plentifully washed with sea-water at the high-spring tides. 

 The white variety is as common there as the type, and both are much 

 eroded at the apex; this is probably due to the action of the salt-water. 



Var. albida. — Waterwynch ; common. 

 Velletia lacustris. — Common in the marshes. It seems to have 

 a preference for the decaying stems and leaves of the Yellow Iris, 

 Reed-Mace, and Bur-Reed, but is occasionally found on the Water 

 Plantain and floating Pond-AVeed. Some specimens are much 

 narrower and more elevated than usual, and may probably be the var. 

 moquiniana (Bourg.). 



Var. albida. — Not uncommon in the Ritec stream, and in the 

 old pit-holes near Hoyle's Mouth. 



Cyclostoma elegans. — Abundant among the Dewberry Brambles 

 at Giltar. There is also a fair-sized colony of the type and \zx%. fasciata 

 and ochrokuca under Privet bushes in the Jubilee Gardens ; the shells 

 are larger and more handsomely marked than the Giltar specimens, 

 though in all probability they originally came from that place. It is 

 common at Pendine. 



Var. ochroleuca. — Jubilee Gardens and Giltar. 



Var. fasciata. — Jubilee Gardens. 

 Valvata cristata. — Abundant, and apparently the only repre- 

 sentative of the freshwater Operculars in the district. The finest 

 specimens measure 5 mm., and come from the Black Rock ditch. 

 This species seems to prefer the grass and plants at the bottom and 

 sides of a ditch, and does not swarm on the under-sides of floating 

 weeds, like the Planorbes ; a scoop with the dredge along the surface 

 will often not produce a single V. cristata, though the ditch may be 

 swarming with them down below. Slightly twisted specimens are not 

 uncommon, and one has the last whorl near the mouth coiled away 

 from the body-whorl, but it is not nearly so liable to deformity as 

 the Planorbes. 



Anodonta anatina var. complanata. — This variety is still fairly 

 plentiful in the Ritec stream near Gumfreston, the locality mentioned 

 by Gwyn Jeffreys (B.C., vol. 1, p. 45). It is rather wonderful that 

 they have not been exterminated, as the bed of the stream at that 

 part is continually being dug out afresh, and the banks are periodi- 

 cally strewn with dead shells. 



Sphaerium corneum. — Common in ditches and streams on the 

 marshes. The largest measure 13 mm., and come from a ditch on 



