Family ZIPHIIDAE--beaked whales Genus =Berardius= Duvernoy--beaked whales _Berardius bairdii_ Stejneger Baird beaked whale Genus =Mesoplodon= Gervais--beaked whales _Mesoplodon stejnegeri_ True Stejneger beaked whale Family DELPHINIDAE--porpoises Genus =Delphinus= Linnaeus--dolphins _Delphinus bairdii_ Dall Baird porpoise Genus =Lissodelphis= Gloger--right-whale porpoises _Lissodelphis borealis_ (Peale) } northern right-whale } porpoise Genus =Lagenorhynchus= Gray--striped porpoises _Lagenorhynchus obliquidens_ Gill striped porpoise Genus =Grampus= Gray--killer whales _Grampus rectipinna_ (Cope) Pacific killer Genus =Grampidelphis= Iredale and Troughton _Grampidelphis griseus_ (Cuvier) grampus Genus =Globicelphalus= Hamilton--blackfishes _Globicephalus scammonii_ (Cope) blackfish Genus =Phocoena= Cuvier--harbor porpoises _Phocoena vomerina_ (Gill) harbor porpoise Genus =Phocoenoides= Andrews--Dall porpoises _Phocoenoides dalli_ (True) Dall porpoise Family PHYSETERIDAE--sperm whales Genus =Physeter= Linnaeus--sperm whale _Physeter catodon_ Linnaeus sperm whale Family KOGIIDAE--pigmy sperm whale Genus =Kogia= Gray--pigmy sperm whale _Kogia breviceps_ (Blainville) pigmy sperm whale Family RHACHIANECTIDAE--gray whale Genus =Rhachianectes= Cope--gray whale _Rhachianectes glaucus_ (Cope) gray whale Family BALAENOPTERIDAE--finback whales Genus =Balaenoptera= Lacépède--finback whales _Balaenoptera physalus_ (Linnaeus) finback whale _Balaenoptera borealis_ Lesson Pollack whale _Balaenoptera acutorostrata_ Lacépède pike whale Genus =Sibbaldus= Gray--blue whale _Sibbaldus musculus_ (Linnaeus) blue whale Genus =Megaptera= Gray--humpbacked whales _Megaptera novaeangliae_ (Borowski) humpback whale Family BALAENIDAE--baleen whales Genus =Eubalaena= Gray--baleen whales _Eubalaena sieboldii_ (Gray) Pacific right whale ACCOUNTS OF SPECIES AND SUBSPECIES =Didelphis virginiana virginiana= Kerr Opossum _Didelphis virginiana_ Kerr. Anim. Kingd., p. 193, 1792. _Type locality._--Virginia _Description._--Slightly smaller than a house cat; body in older animals heavy and fat; tail long, naked, scaled and prehensile. Ears large, naked and black with white tips; muzzle elongate and pointed; color of fur variable; overhair usually white and underfur white tipped with black; guard hairs long and coarse but underfur soft and dense; forefoot with opposable thumb; females with abdominal pouch.