472 AXEL A. OLSSON 



Family Veneridae 



Subgenus Planitivela of Tivela 266 



Type species, Tivela planulata (Broderip and Sowerby) 



Subgenus Iliochione of Chione 297 



Type species, Venus subrugosa Sowerby 



Subgenus Tropithaca of Protothaca 305 



Type species, Protothaca grata (Say) 



Subgenus Antinioche of Nioche 310 



Type species, Nioche (Antinioche) beili, new species 



Genus Colonche 311 



Type species, Colonche ecuadoriana, new species 



Family 



Genus Halodakra 319 



Type species, tCirce subtrigona Carpenter 



Family Tellinidae 



Genus Lyratellina 383 



Type species, Tellina lyra Hanley 



Sub'^enus Pisostrigilla of Striailla 390 



Type species, Strigilla pisiformis (Linn6) 



Subgenus Simplistrigilla of Strigilla 390 



Type species, Strigilla strata, new species 



Genus Elpidollina 407 



Type species, Tellina decumbens Carpenter 



Genus Hertellina 409 



Type species, Tellina (Scissula) nicoyana Hertlein and Strong 



Genus Psammothalia 416 



Type species, Tellina cognata C. B. Adams 



Genus Ardeamya 417 



Type species, Tellina columbiensis Hanley 



Genus Austromacoma 419 



Type species, Macoma constricta Bruguiere 



Family Myacidae 



Subgenus Austroplatyodon of Platyodon 424 



Type species, Platyodon (Austroplatyodon) australis, new species 



Family Corbulidae 



Genus Serraeorbula 433 



Type species, Serracorbula tumaca, new species 



