PKOCLEDINGS OF UMTED STATES NATIONAL MUSEUM. 343 

 Extra-limital Species. 

 Genus I'ATELLA Linne. 



Faidla Liu. S. N. «-d. x, 1758.— Dall, 1, c. p. 266, 1871 (full synouymy). 

 Patella vulgata. 



P. vulgata Liu, Syst, Nat. ed, xii, p. 1258.— Dall, 1. c. p. 268, pi. 15, f. 23, 1861. 



British and North European seas from the Mediterranean to the 

 Northern Lofoten Islands, between tides. Type of the genus. 



Genus PATINA Leach. 



Fatma Leach, MSS. 1819; Moll. Gt. Brit. 1852, p. 223.— Dall, 1. c. p. 279. 



Helcion Jeffreys, not Montfort. 



Nacella H. & A. Adams, Sars, not Schumaclier. 



Patina pellucida. 



Patella pellucida Lin. S. N. ed. xii, p. 1260. 



Patina peXluciM Leach, 1. c. p. 224, 1852.— Dall, 1. c. p. 280, pL 16, f, 20, 1871. 



British and North European seas, northward to Lofoten j in most 

 cases living on the stalks and fronds of large fuci. 

 December 16, 1878. 



LIST OF THE FIGURES. 



Plate I. 



1. Leptocliiton cancellatm Sby., Alaska: a, major lateral from above. 



2. Eanleyia mendicaria Mighels & Adams, Casco Bay, Maine. 



3. Trachydermon ruber Lowe, Greenland: a, major oncinus from belcWt 



4. Trachydermon albus Lin., Alaska. 



5. Tonicella lineata Wood, Alaska. 



6. T. marviorea Fabr., Greenland. 



7. T. aubmamiorea Midd., Alaska. 



8. Schizoplax Brandtii Midd., Aleutian Islands. 



9. Choetopleura gemma Cpr., California. 



10. C. t Harticegii Cpr., California. 



Plate II. 



11. Maugcrella consptcua Cpr., California. 



12. Sten(rradsia viagdalenensis Hinds, California. 



13. Stenoplax limaciformis Sby., west coast of Mexico. 



14. Ischnochiton reg2ilaris C]yr., California. 



15. Ischnochitan Coo2)cri Cpr., California. 



16. IschnocMton intcrstinctus Gld., Alaska. 



17. Ischvoradsia trifida Cpr., Alaska: a, cusp of major lateral from above. 



18. Lepidopleurus Mcrtcnsii Midd., Alaska: a, rhachidian in situ. 



19. Lepidoradsia au^tralis Sby., Port Jackson, Australia. 



20. Callistochiton palmulatus Cpr., California. 



Plate III. 



21. Pallochiton lanugitionus Cpr., California. 



22. Chiton articulatus Sby. : a, side view of rhachidian tooth. 



23. Ischnoplax pectinatus Sby.. West Indies. 



