Key:  Family Veneridae

Phylum Mollusca
 Class Bivalvia
  Subclass Heterodonta
   Order Veneroida

Taken primarily from  Kozloff, 1987, 1996 p. 280 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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Lower taxonomic level Main Page Alphabetic Index Systematic Index Glossary
1a  With distinct radial ribs (these may, however, be delicate or faint) 2
1b Without radial ribs 4
2a Radial ribs typically more prominent than the concentric ridges (but this is not always the case); hinge ligament about 1/3 the length of the shell; length not more than 6 cm 3
2b Radial ribs less prominent than the concentric ridges; hinge ligament nearly half the length of the shell; length sometimes attaining 8 cm Protothaca (Callithaca) tenerrima
3a With a row of small teeth on the inside of the valves close to their ventral margins; interior of valves whitish, without a purple stain near the posterior end Leukoma staminea
3b Without a row of teeth on the inside of the valves close to their ventral margins; interior of valves (often) yellowish, with a purple stain near the posterior end. [In key as Tapes (Ruditapes) philippinarum] Venerupis philippinarum
4a Length less than 8 mm; height usually more than 3/4 the length; angle formed by the dorsal margin at the umbones not more than 110 degrees; 3 cardinal teeth on the hinge plate of both valves; embryos brooded internally 5
4b Length generally greater than 2 cm; height not often more than 3/4 the length; angle formed by the dorsal margin at the umbones more than 110 degrees 8
5a
5b
6a
6b
7a
7b
8a Concentric ridges conspicuously raised; posteriormostcardinal tooth on right valve not bifid 9
8b Concentric lines of growth not conspicuously raised, the exterior of the shell thus nearly smooth; posteriormostcardinal tooth on right valvebifid (length up to about 6 cm) Compsomyax subdiaphana
9a Umbones at the end of the second 1/5 of the shell from the anterior end; periostracum yellowish, polished; length up to 2.5 cm; subtidal Liocyma fluctuosa
9b Umbones at the end of the first 1/5 of the shell from the anterior end; periostracum not yellowish and not polished; length generally exceeding 3 cm 10
10a Shell closing tightly at the posterior end; concentric ridges bent in the direction of the umbones; length up to 10 cm; subtidal Humilaria kennerlyi
10b Shell gaping slightly at the posterior end; concentric ridges, even if sharp, not bent in the direction of the umbones; length often exceeding 10 cm; common intertidally Saxidomus gigantea
(S. giganteus in key)



Taxonomic Levels Represented in This Key:

  Humilaria kennerlyi
  Leukoma staminea
  Saxidomus gigantea
  Venerupis philippinarum

  Introduced, not in key:
  Mercenaria mercenaria



Page created by Dave Cowles, 2005
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