In which one of the following, the genus name and its two characters are correctly matched?

Torpedo is commonly called electric ray. It has electric organs. Scales in Chondrichthyes are placoid. Ascidia is a urochordate. Notochord is present but vertebral column is absent in urochordates and cephalochordates. Tympanum is absent in fishes (e.g., Catla). Crocodiles have a four-chambered heart.