1. Of or related to Old World monkeys that have nostrils together and opening downward
   - catarrhine

See also: catarrhine

• family Ipidae
• family Irenidae
• family Iridaceae
• family Isoetaceae
• family Istiophoridae
• family Isuridae
• family Ixodidae
• family Jassidae
• family jewels
• family Juglandaceae
• family Juncaceae
• family Juncaginaceae
• family Jungermanniaceae
• family Kalotermitidae
• family Kasuwonidae
• family Kinosternidae
• family Kyphosidae
• family Labiatae
• family Labridae
• family Lacertidae
• family Lactobacillaceae
• family Lactobacteriaceae
• family Lamiaceae
• family Laminariaceae
• family Lamnidae