People have been warned not to touch the jellyfish (picture from MCA)
More than 70 potentially dangerous Portuguese men-of-war jellyfish have been washed up along the Dorset and Devon coastlines.
Coastguards were alerted to the "unprecedented" high numbers of the creatures on Tuesday night.
In Devon, 39 were recovered in Barnscombe, eight in Seaton and five in Beer, while in Dorset, 20 in West Bay.
Coastguards urged the public to report any further sightings but not to touch the creatures.
The long tentacles of a man-of-war, which hang from a balloon-like float resting on the surface, can produce an extremely painful and potentially fatal sting.
The creature is not a true jellyfish, but a siphonophore - a single animal made up of a colony of organisms - which normally lives far out in the ocean.
A Portland Coastguard spokesman said: "They are nasty things and we want to warn people not to touch them.
"They may appear dead on the shore but stay alive for days and can still sting.
"It is very unusual to see so many and we think they may have been blown onto shore as they drift in the currents.
"With the wind turning round we are not expecting too many more to wash up."
He advised anyone who finds them to alert a lifeguard or coastguard.
A spokesman for West Dorset District Council said: "We had some wash up last year but not on this scale, it is unprecedented.
"If anyone does get stung they must seek medical attention."
He said those recovered have been disposed of by the Environment Agency.
Man-of-war colonies are usually found in places such as the Indian Ocean and the Caribbean.