Bulla. 

 Fig. 

 • 17. B. CranchiI, Leach. — B. punctura and striata.- — Brit. co. gen, 

 Devon, Aberdeen, Cork, etc., 50 to 100 fath., Mr. Spirally 

 puncto-striated. 



18. B. cornea, Larnk. — B. hydatis (as of Linn.), B. navicula, B. am- 



pulla, Haminea hydatis. — South Brit, co., to 50 fath., C. S. Eu. 

 Broad, thin. 



19. B. hydatis, Linn, .~~Haminea elegans, — Guernsey and Mediterra- 



nean. Narrower and more solid than B. cornea. 



Philine. 



20. P. aperta, Linn. — P. Bulla, Bulla? a, and Lobaria a,, quadripartita, 



guadrilobata, and Planciana. — Brit. co. gen., C. S. Eu. Large, 

 smooth. 



21. P. scabra, Muller, — Bulla and Scaphander scabra, pectinata, 



dilatata, and catenulifera. — Northumberland, Zetland, Ireland, 

 etc., Mc, 5 to 50 fath. N. Eu. Oblong, serrated. 



22. P. quadrata, S. Wood. — Bullaa and P. scutulum. — Zetland, etc., 



10 to 100 fath., E. Striated. 



23. P. catena, Mont. — -Bulla and Bullaa c, angustata, and punctata. 



■ — Brit. co. generally, Mr., to 40 fath. With chain-like sculpture. 



24. P. punctata, Clark. — Bulla and Bullaa. — Devon, Swansea, Aber- 



deen, Clare. In sand, 60 fath., Mc. With punctured sculpture. 



25. P. pruinosa, Clark. — Bulla and Bullaa. — Devon, Northuinb., 



Hebrides, etc. Mud, 20 to 70 fath. N. Eu. 



Scaphander. 



26. S. lignarius, Linn. {Bulla.) — B. oblonga. — Brit. co. generally. 



1 to 50 fath. N. and S. Eu., C. 



27. S. zonatus, Turt. {Bulla.) — Young specimen taken at Zetland by 



Mr. Jeffreys, resembling older Norwegian specimens. More oval 

 than S. lignarius. Spire umbilicated. 



Aplysia. 



28. A. hybrida, Sowerby, — Laplysia depilans, A. depilans and punctata. 



— Brit. co. generally. Among seaweeds, to 6 fath., C. 



Pleurobuanchus. 



29. P. membranaceus, Mont. {Lamellaria.) — Devon, Arran, Cork, etc. 



Low-water, Mr. Broad, flexible. 



30. P. plumula, Mont. {Bulla.) — Guernsey, Devon, Skye, etc. Littoral, 



R. Narrow, less flexible. 



Spirula. 



31. S. Peronil— Once taken near Swansea, imperfect. 



