340 Mr. J. G. Jeffreys on the recent species of Odostomia 



dain, Berwickshire (Maclaurin). Isle of Man (Forbes). Tynemouth 

 (Alder). Swansea and adjacent bays ; Tenby ; Weymouth ; Ex- 

 mouth ; Scarborough ; Bantry Bay ; Lerwick. West coast of Scot- 

 land ; Arran Isle, co. Galway (Mr. Barlee). Northumberland coast 

 (Mr. Richard Howse). Torquay (Dr. Battersby). 



Var. a. ultimo anfractu subcarinato ; apertura subrhom- 

 boidea. 



Falmouth ; Penzance ; Swansea and adjacent bays ; Tenby ; White- 

 sand Bay, Cornwall; Oban; Lerwick Sound, in from five to ten 

 fathoms ; Skye. West coast of Scotland (Mr. Barlee). Torquay 

 (Dr. Battersby). 



Var. b. spira breviore ; apertura subrhomboidea. 



Swansea and adjacent bays ; Tenby; Oban ; Skye ; Lerwick Sound, 

 in from five to ten fathoms. West coast of Scotland (Mr. Barlee). 

 Torquay (Dr. Battersby). 



A very common species. 



I subjoin a description of the animal of var. b. 



Animal luteum ; tentacula breviuscula, cylindrical complanata, 

 ad basim eorum divergentia, aliquantulum producta ultra susten- 

 taculum gradiente animali; oculi bini, parvi, juxtapositi in me- 

 dio spatii inter tentacula ad eorum basim ; proboscis antice ro- 

 tundatus ; sustentaculum angustum, longiusculum, antice latius 

 et aliquantulum lobatum ; operculum corneum, subspirale. 



Animal hoc solet, ut cseteri prctinibranchiati gasteropodes, 

 supra dorsum natare et gradi oculis retractis sub anteriore parte 

 testse perquam illi conspicui sunt. 



It has the same faculty as many other of the pectinibranchous 

 gasteropods of swimming on its back, and (like the animal of 

 Rissoa glabra described by Mr. Alder in the l Annals of Natural 

 History/ or Turbo nivosus of Montagu) it has occasionally the 

 habit of walking with its eyes retracted within the shell, through 

 which they are distinctly seen. The specific difference between 

 the animals of this species and unidentata is very slight. 



12. Odostomia unidentata. 



Turbo unidentatus, Mont. 324. 



Valuta unidentata, Mat. and Rack, in Linn. Trans, viii. 131 ; 

 Dillw. i. p. 508. 



Turbo pallidus, Turt. 222. 



Odostomia plicata, Fl. 310; Thorpe, 35. fig. 13. 



Melania (subg. Eulima) unidentata, Forbes, Mai. Mon. 15. 



Turbonilla oscitans, Lov. 19. 



Odostomia unidentata, Alder, Cat. 50. 



Salcomb Bay (Mont.). Dunbar (Laskey). Western coasts and 

 Dublin Bay (Turton). Douglas, Isle of Man (Forbes). Swansea 

 and adjacent bays ; Tenby ; Ilfracombe ; Scarborough ; Oban ; Loch 



