These were their descendants:Ishmael’s firstborn son was Nebaioth; the others were ¹  Kedar, Adbeel, Mibsam,

The sons of Ram, Jerahmeel’s firstborn, were Maaz, Jamin, and Eker.

The sons of Reuben, Israel’s firstborn: Hanoch, Pallu, Hezron, and Carmi.

The sons of Jerahmeel, Hezron’s firstborn, were Ram, the firstborn, Bunah, Oren, Ozem, and Ahijah.

These were the descendants of Caleb. The sons ¹  of Hur, the firstborn of Ephrath: ²  Shobal, the father of Kiriath Jearim,

Penuel was the father of Gedor, and Ezer was the father of Hushah. These were the descendants of Hur, the firstborn of Ephrathah and the father of Bethlehem.

Hosah, one of the descendants of Merari, had sons: The firstborn Shimri (he was not actually the firstborn, but his father gave him that status),

The sons of Judah: Er, Onan, and Shelah. These three were born to him by Bathshua, ¹  a Canaanite woman. Er, Judah’s firstborn, displeased the Lord, so the Lord killed him. ² 

The sons of Reuben, Israel’s firstborn – (Now he was the firstborn, but when he defiled his father’s bed, ¹  his rights as firstborn were given to the sons of Joseph, Israel’s son. So Reuben is not listed as firstborn in the genealogical records. ²