This looks like them. Unfortunately no town names for place of birth...
HO107/2459 Folio 298 Page 30
Merthyr Tydfil, Glamorgan, Wales
Address: ? (There is no address next to their entry. There is one at the top of the page, but I can't decipher it: New Hermes(?) St. Cout?? )
Will Davis, Head, 31, Collren?, b. Carmthen
Jane ", Wife, 30, b. "
Mary ", Daur, 7 (or 9?), b. "
John ", Son, 6, b. "
David ", Son, 4, b. "
Evan, Son, 1, b. Glan Dowlais
There are at least 4 Evan Davies born in Dowlais in 1850 - just in case you weren't sure about the parents names, there are other possibilities.
MJP