THE BRITISH NATURALIST. 



137 



THE MOLLUSCA OF NOTTINGHAMSHIRE. 



BY W. A. GAIN. 



(Continued from page 48.) 



Order PULMONOBRANCHIATA. 



Family LIMNAEID^E. 

 Genus Segmentina, Fleming. 



S'egmentina nitida, Mull. (=Planorbis lineatns, Walker.) — Taken in 

 the lake at Highfielcl House by Mr. Lowe. Dodd and Musson. Of 

 rare occurrence at Beeston (Musson). 

 Genus Planorbis, Guettard. 



Planorbis fontaniis, Lightfoot (=Pl. nitidus, Jeff.) — Occurs in several 

 ponds, principally in the neighbourhood of Nottingham, usually in 

 small numbers, in two instances only Mr. Musson records it as plenti- 

 ful. Also in the Lenton canal. I have taken this species pretty 

 freely in the lake at Clumber, and have found it in the rejectamenta 

 of the river Trent. 



Planorbis nautileus, L. — Widely distributed, and often found in large 

 numbers. 



Var. crista, L. — Near Worksop (Musson). 



A var., probably crista, is also mentioned in the catalogue of Dodd 

 and Musson as occurring at Bulwell. 



Planorbis albus, L. — Common, and widely distributed. 



Planorbis parvus, Say. (=Pl. glaber, Jeff.) — Lake at Thorsby, and 

 one specimen from the lake at Clumber (Musson). 



Planorbis rotundatus, Poiret. (=Pl. spirorbis, Jeff.) — Abundant, and 

 widely distributed. 



Planorbis vortex, L. — Plentiful in ponds, &c, throughout the county. 



Var. compressa, Mich. — Stanton-on-the- Wolds (Lowe). 



Planorbis carinatus, Mull'. — Common, and widely distributed. 



Var. disciformis, Jeff. — I have taken this variety in the canal at 

 Newark. 



Planorbis nmbilicatus, Mull. (=Pl. complanatus, Jeff.) — Common 

 throughout the county. 



Var. rliombca, Turt. — Bawtry. Ditch in Lenton meadows (Musson). 

 Planorbis corneas, L. — Common, and widely distributed. 

 Planorbis contortus, L. — Widely distributed. 



Sub-family PHYSINiE. 

 Genus Bullinus, Adamson. 



Bullinus hypnorum, L. — Common throughout the county. 



