Key to Family Nucellidae

Phylum Mollusca
 Class Gastropoda
  Subclass Prosobranchia
   Order Neogastropoda
    Suborder Rachiglossa

Taken primarily from  Kozloff, 1987, 1996  p. 221 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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1a  Outer lip of the aperture with a sharp tooth slightly below the middle (smaller specimens may, however, lack the tooth); with interrupted dark spiral bands (uncommon north of California) (picture) Acanthina spirata
1b Outer lip of aperture without a sharp tooth (picture ); without interruped dark spiral bands  2
2a Axial sculpture consisting of frilly lamellae (picture); spiral sculpture (which may be obscured by the lamellae) consisting of 1 or 2 prominent ridges on each whorl (height up to 10 cm) (picture ) Nucella lamellosa
2b Axial sculpture, if noticeable, cosisting either of broad ribs or low wrinkles; spiral sculpture consisting either of 1 or 2 prominent ridges on each whorl, or of numerous closely spaced ridges 3
3a Spiral sculpture consisting of 1 or 2 prominent ridges on each whorl (but the lower part of the body whorl usually has several smaller ridges), the whorls flattened between the ridges and the sutures, thus appearing angled; height up to about 10 cm. [Specimens that fit under this choice are typical of situations where currents are strong or where there is considerable wave action--in which case the axiallamellae may not be present]. (picture Nucella lamellosa 
3b Spiral sculpture consisting of closely spaced ridges (in some specimens of Nucella emarginata, however, the ridges are obscure); height rarely exceeding 3 cm  4
4a Spiral ridges generally of 2 sizes, the smaller ones alternating with the larger ones; whorls not separated from one another by a deep groove (picture 5
4b Spiral ridges generally of nearly equal size; whorls usually separated from one another by a deep groove  Nucella canaliculata
5a Shell relatively thin; width of the aperture about half the diameter of the shell (not likely to be found south of the northern part of Vancouver Island) Nucella lima
5b Shell relatively thick, the thickness being especially noticeable on the outer lip of the aperture; width of aperture (the actual opening) less than half the diameter of the shell (interior of aperture often purplish brown; common) (picture) (Nucella emarginata in Kozloff key) Nucella ostrina

Taxonomic Levels Represented in This Key:

 Acanthina spirata
 Nucella canaliculata
 Nucella lamellosa
Nucella ostrina

Page created by Nathaniel Charbonneau, 7-2002
Edited by Hans Helmstetler 1-2003, Dave Cowles 2005, 2009