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Click on photo to enlarge.  Scale line in photo equals 1cm unless otherwise specified.
* Species which are commonly encountered on the beach.


Lucinidae
Lucinoma annulata
Big Fishtrap Cove, WA
















Lucinoma annulata
(Reeve, 1850)
Western Ringed Lucine
intertidal to 750m          size to 82mm
northern Mexico to central Alaska & Japan
This is occasionally found intertidally.
The prominent growth rings are easily eroded.
On this species the growth rings represent
growth intervals, not years.
(previous name - Lucina annulata)







 












Adontorhina sphaericosa
Boca de Quadra, AK
Adontorhina sphaericosa
Valentich-Scott, 1986
Inflated Axinopsid

subtidal, 95-3000m          size to 1.6mm
central California to SE Alaska
This tiny shell is highly inflated, almost a round ball.  The hinge plate is moderately broad with irregular granules.

Thyasiridae
Adontorhina cyclia
Pribilof Islands, AK
Adontorhina cyclia S.S. Berry, 1947
Circle Axinopsid
subtidal, 12-3000m          size to 3mm
north Mexico to north Bering Sea; Sakhalin Island to southern Kuril Islands
This tiny shell is moderately inflated and has fine granules on the hinge plate.



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This page last revised: 6-29-2024




Conchocele bisecta
San Juan Islands, WA




Thyasira flexuosa
off central Oregon coast
Thyasira flexuosa
(Montagu, 1803)

Flexuose Cleftclam
subtidal, 20-3000m          size to 12mm
circumboreal and panarctic; reaches south to
southern California, Florida, north Africa and Japan
The shell form is extremely variable.  It has very
fine sculpturing.  It has many synonyms, and with
further study, it may be determined there is more
than one species.
(synonyms - Tellina flexuosa, Cryptodon barbarensis, Cryptodon insignis,  Cryptodon planus, Axinulus inaequalis)











Conchocele excavata Conchocele excavata
                       Gulf of California, Mexico                                          offshore north Washington coast
Channelaxinus excavata (Dall, 1901)
Excavated Cleftclam
subtidal, 800-2520m          north Mexico to north Washington          size to 24mm
This small deep water shell has a distinct cleft on the anterior end.
(synonyms - Conchocele excavata, Thyasira excavata, Thyasira tricarinata)

Mendicula ferruginosa
off central Oregon coast
Mendicula ferruginosa (Forbes, 1844)
Rusty Axinopsid
subtidal, 40-4475m          size to 3.2mm
Circumboreal and Arctic; central California to Pribilof Islands; Cape Hatteras, NC to Georges Bank; Mediterranean; Eastern Atlantic; Cape Verde, Angola and Argentine basins
This widespread species is pale yellow.  But it's thin periostracum is usually covered with a thick, reddish-brown coating.
(synonyms - Aligena (Odontogena) borealis, Cryptodon ferruginosum, Axinus ferrugineus, Thyasira ferruginea, Cryptodon rotundatus)










Conchocele bisecta (Conrad, 1849)
Giant Cleftclam
subtidal, 50-750m          size to 100mm
northern California to Bering Sea;  Sea of Japan to Sea of Okhotsk
This is found on mud bottoms.  It is a chalky shell with a prominent cleft on the anterior end.
(synonym - Conchocele disjuncta)








Axinopsida serricata
Kasitsna Bay, AK
Axinopsida serricata
(Carpenter, 1864)

Lenticular Axinopsid

low intertidal to 275m          size to 8mm
Circumboreal & Panarctic; reaches south to north Mexico, north Japan, & Labrador
This shell can be highly variable in shape.  It has a strong central tooth.  Lives in mud.
(synonym - Cyptodon serricatus)





















Parvilucina tenuisculpta Parvilucina tenuisculpta
                                      Barkley Sound, BC                                                         BC
Parvilucina tenuisculpta
(Carpenter, 1864)
Fine-Lined Lucine
intertidal to 300m     northern Mexico to northern Alaska          size to 15mm
This is infrequently found intertidally.  It prefers mud with high organic content.  The growth lines are
very fine and closely spaced.
(previous name - Lucina tenuisculpta)

Bivalves 

Family Lucinidae & Thyasiridae