Description of two new species (Bivalvia: Vesicomyidae, Verticordiidae) from a cold seep in the South China Sea

In this paper, we describe two new deep-sea bivalve species belonging to the families Vesicomyidae and Verticordiidae, respectively. They were collected during a survey of the Haima Methane Seep at the Qiongdongnan. Basin on the northwestern slope of the South China Sea, China, at a depth of 1,400 m. Vesicomya rhombica new species is small in size and characterized by its rhombic shell shape and a slight furrow on the surface of the posterior shell region, running from the umbo to the postero-vental margin. It is the first species of this genus recorded from Chinese waters. Spinosipella xui new species has a long, lamellar posterior lateral tooth on the right valve, 13 strong radial ribs, and conspicuous spines on the shell surface. The latter constitutes one of three species of this genus living in Chinese waters.