Exploring species in United States of America
Abbot's Bagworm Moth 
Abbreviated Button Slug 
Aberts squirrel 
Aborted entoloma 
Abrupt Epiblema Moth 
Abutilon theophrasti 
Acadian hermit crab 
Acalitus ferrugineum 
Acalymma vinctum 
Acanthocephala terminalis 
Acanthoscelidius acephalus 
Acanthus balcanicus 
Acarospora fuscata 
Acer circinatum 
Aceria fraxini 
Aceria trinema 
Aceria triplacis 
Achemon sphinx 
Achlys triphylla 
Acholla multispinosa 
Acilius mediatus 
Ackee apple 
Acleris cornana 
Acleris fragariana