摘要:Cymbasoma belizense sp. n. is described from an adult female collected during a zooplankton survey of the Corozal Bay Wildlife Sanctuary (CBWS), adjacent to Chetumal Bay, a large binational embayment on the northwestern Caribbean Basin. The new species is a member of the Cymbasoma longispinosum species-group; it resembles C. chelemense Suárez-Morales & Escamilla, 1997 from the Gulf of Mexico and C. jinigudira Suárez-Morales & McKinnon, 2014 from Australia. This is the eighth nominal species known in this species-group, the second one recorded from the Caribbean Sea Basin, and the first one in the Belizean coast. The new species is distinguished by a combination of characters, including the body proportions, the structure and armature of the fifth legs, the cephalic ornamentation, with a fringe of faint cuticular striae, the relative length and bifurcation point of the ovigerous spines, and details of the antennule armature. Comparative comments and data including the distribution and taxonomical characters of members of this species-group are presented. Records of this nominal species from different geographic areas should be revised carefully because they could represent undescribed species. A key to the females of the currently known species of this group also provided.