99 4.0 D2.
There are 2 hard plastic tubes with 180 degree bends on the ends.
They come from behind the motor, right near the end of the passanger side head.
Picture is sideways.
They are small, perhaps 1/4" OD at the max.

2nd picture shows my blown headgasket, random misfires on 4 and 6 my ***! My valley pan gasket was puffed up like a pillow. The wrench I found under the gasket distracted me from everything. And since I recieved two packs of short head bolts, gotta fill some time till the right ones get here. So I will start small, them 2 tubes??

 

They are breather tubes.

 

Ok. Thank you.
Was worried something was missing.

 

Well, you should wonder about what they do and how to maintain them. Everything on a Rover needs service it seems from time to time. Those vent the front axle and the transfer case, the rear axle line runs forward and ends near the transfer case. At the other end of these little vent pipes is a "banjo" bolt. Vapor cooked off from the capitive space lubricant (diff oil, etc.) comes out. But condensation, dirt, insects, creek water, etc. can go in. When plugged up, no vent. The laws of physics pop up, and the slight pressure in the now sealed container causes oil to be pushed out thru seals in strange places. Some guys who do a lot of wading extend the rear one to a higher point on the vehicle. Here's pix of blocked one. When changing diff oil, etc., good time to inspect and service.