Key:  Family Tellinidae

Taken primarily from  Kozloff, 1987, 1996 p. 279 (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	Hinge plate with lateral teeth (these may be small) in addition to the cardinal teeth	2
1b	Hinge plate without lateral teeth	5
2a	Shell about twice as long as high; length commonly more than 1 cm	3
2b	Shell much less than twice as long as high; length up to 1 cm or slightly more	4
3a	Interior of both valves with a ridge just behind the scar of the anterioradductor muscle; length up to about 2 cm	Tellina (Angulus) modesta
3b	Neither valve with a ridge behind the scar of the anterioradductor muscle; length up to about 5 cm	Tellina (Moerella) bodegensis
4a	Shell slightly more than 1.5 times as long as high; valves becoming narrowed toward the posteroventral corner; exterior white to pink	Tellina (Angulus) carpenteri
4b	Shell about 1.3 times as long as high; valves rounded posteriorly; exterior whitish or yellow, but interior often pink	Tellina (Cadella) nucleoides
5a	Length about twice the height; rare	Macoma (Psammacoma) yoldiformis
5b	Length much less than twice the height; common intertidal and subtidal species	6
6a	Posterior portions of both valves distinctly bent to the right (photo)	Macoma (Heteromacoma) nasuta
6b	Posterior portions of valves not bent to the right	7
7a	Periostracum polished, usually transparent; hinge ligament not more than 1/4 the length of the slope from the umbones to the posterior end; length commonly exceeding 5 cm, and sometimes attaining 10 cm	Macoma (Rexithaerus) secta
7b	Periostracum not polished or transparent; hinge ligament at least 1/3 the length of the slope from the umbones to the posterior end; length not often exceeding 5 cm	8
8a	Outline of valves almost perfectly oval; the posterior end nearly as rounded as the anterior end; valves (especially the interior) often yellow, pink, or bluish; length to about 2 cm.	Macoma (Macoma) balthica
8b	Outline of valves not almost perfectly oval, the posterior end being narrowed and less rounded than the anterior end; valves whitish, except for the brown periostracum; length up to about 5 cm	Macoma (Heteromacoma) inquinata

  Macoma balthica
  Macoma nasuta
  Tellina bodegensis
  Tellina (Angulus) modesta