PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 343 

 Extra-Umital Species. 

 Genus PATELLA Linne. 



Patella Lin. S. N. eel. x, 1758.— Dall, 1. c. p. 266, 1871 (full synonymy). 

 Patella vulgata. 



F. 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 MediteiTanean to the 

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



Genus PATINA Leach. 



Patina Leacli, MSS. 1819 ; Moll. Gt. Brit. 1852, p. 223.— Da^l, 1. c. p, 279, 



Helcion Jeffreys, not Montfort. 



Nacdla H. & A. Adams, Sars, not Schumacher. 



Patina pellucida. 



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



Patina peUucida Leach, ]. c. p. 224, 1852.— Dall, 1. c. p. 280, pi. 16, f. 20, 1871. 



British and North Eurox)ean seas, northward to Lofoten; in most 

 cases living on the stalks and fronds of large fuci. 

 December 16, 1878. 



LIST OF THE FIGURES. 



Plate I. 



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



2. Hanleyia mendicaria Mighels & Adams, Casco Baj^, Maine. 



3. Tradujdermon ruber Lowe, Greenland: «, major uncmus from below. 



4. Tracliydcrmon albus Lin., Alaska. 



5. Tonicella Uneata Wood, Alaska. 



6. T. marmorea Fabr., Greenland. 



7. T. submarmorea Midd., Alaska. 



8. ScMzoplax Brandtii Midd., Aleutian Islands. 



9. Cliatopleura (jemma Cpr., California. 



10. C. f Hartwefjii Cpr., California. 



Plate II. 



11. Maugerella conspicua Cpr., California. 



12. Stenoradsia magdalenensis Hinds, California. 



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



14. IscknocMton regularis Cpr., California. 



15. Ischnocliit/)n Cooperi Cpr., California. 



16. Jaclmoclnton interstinctus Gld., Alaska. 



11 .■sLschnKyradsia trifida Ci)T., Alaska: a, cusp of major lateral from above. 



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



19. Lepidoradsia australis Sby., Port Jackson, Australia. 



20. CallistocJiiton palmiilatas CiJr., California. 



Plate III. 



21. PallocJiiton lanuginosus Cpr., California. 



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



23. Ischnoplax pectinatua Sby., West Indies. 



