4 bivalves from Madagascar

[conchylinet]

Hello,
I have these shells from southwestern Madagascar. Any ID help would be appreciated.

<img src="http://www.conchylinet.com/Images/Misc/5964ui.JPG" alt="http://www.conchylinet.com/Images/Misc/5964ui.JPG" style="border:0" />
36mm Veneridae

<img src="http://www.conchylinet.com/Images/Misc/5956ui.JPG" alt="http://www.conchylinet.com/Images/Misc/5956ui.JPG" style="border:0" />
28.5mm, light & translucent, undetermined family

<img src="http://www.conchylinet.com/Images/Misc/5961ui.JPG" alt="http://www.conchylinet.com/Images/Misc/5961ui.JPG" style="border:0" />
65mm Veneridae (closeup of the sculpture on right)

And that last one:
<img src="http://www.conchylinet.com/Images/Misc/5953ui.JPG" alt="http://www.conchylinet.com/Images/Misc/5953ui.JPG" style="border:0" />
9mm, undetermined family


Ta.
Pierre  <span class="petit">--Last edited by conchylinet on 2010-09-07 20:22:05 --</span>

[mike]

Nr 1: looks like Globivenus toreuma
Nr 3: could be Antigona chemnitzii

Mike

[paul monfils]

Possibilities for the others.  I am not certain about either one. #2 perhaps Mactra ovalina; #4 perhaps Macoma retrorsa.

[conchylinet]

Thank you Mike and Paul.
It helps a lot. However i am a bit puzzled with the Antigona. It seems to exist other species similar to chemnitzii (A clathrata, A reticulata, etc.). Has anybody keys to tell them apart ?

[mike]

Nope, I don't know of any identification keys to Antigona/Periglypta species... I can imagine the books "Bivalves of Australia, Vol 1&2" having that kind of key, but I don't have these books. ...So most of my own Antigonas remain unidentified

Mike

[mike]

Hello Pierre,

recently I got my hands on the new "Compendium of Bivalves" book and your Antigona looks very much like the Antigona crispata (Deshayes 1853) pictured in that book. The distribution area of this species (Indian Ocean) fits too.

Mike