Thanks, All!
I discovered the image in the Philippine book - it was there all along, assuming it is correct. The mystery is solved - one of the shells I bought was misidentified (I know it is "Cardium" belcheri but have to check the correct genus). So I have no Trachycardium angulatum; that label was wrong. Now I can retype all the cards; I have belcheri, magnum, alternatum, and pristipleura, no angulatum.
Thabks anyway,
Linda