The Silurians

The Silurians are an intelligent reptilian relative to the Sea Devil , possessing a third eye in the centre of their head through which they focussed a ray of mental energy that could kill. Also (like the Sea Devils) fearing global devastation from the moon, they built an underground shelter and they also overslept for millions of years. Until eventually a colony beneath Wenley Moor was awakened by the activities of an underground atomic research station. The old Silurian leader supported the Doctor's efforts to negotiate peace between the two races, whilst the more fanatical element attempted to destroy mankind. The Brigadier completely destroyed this colony and the Doctor was disgusted. the Silurians, now totally committed to the extinction of  man, revived a colony of Sea Devils and launched a combined attack on an Earth Sea Base. The Doctor had no choice, but he destroyed them with a gas. 

The Silurians were in The Silurians and Warriors of The Deep.