In pheretima, the open type of nephridia are located in these segments :

$\begin {array} {1 1} (1)\;4th, \: 5th \: and \: 6th & \quad (2)\;2nd\: to\: the \: last \\ (3)\;16th \: to \: the \: last & \quad (4)\;7th, \: 9th\: and \: 13th \end {array}$