Ƙirƙiri wani nau'i mai mahimmanci na wannan jumla Layin pallial alama ce (layin ) a cikin kowane bawul na kwandon kwalliya na mollusk bivalve.
Tabbas, wani nau'i mai rikitarwa na jumla shine "Layin pallial alama ce a cikin ciki na bawul din kwalliyar mollusk inda tsokoki na mantle suka haɗa, wanda a cikin clams tare da tsokoki biyu masu haɗawa yawanci suna haɗuwa da alamun inda tsokoki masu haɗawa suka haɗa. "