No, they are like the ordinary GLS lamp, but the top is slightly flattened. I suppose a similar shape to the R50, but not quite so long a 'neck', and they do not have a reflector. Not very descriptive - sorry!
They were very popular in the 60's and 70's, as Paul suggests, but they are now more a decorative issue. I'm not sure why they were 'favoured', but I recall seeing an adverrt for them years ago that said they gave out more light. Lord knows how!
If hindsight were foresight, we'd all be millionaires!
uksparky, Are you talking about the "Softline" range of bulbs?. Made to be gentler on the eye, while working or not!. My favourite is Metal-Halide, to be honest.
The lower group of bulbs in this picture aren't quite the exact shape I remember, but about the closest I can find with a quick search. (The ones used in Britain more often had BC bases rather than ES, as you would expect.)
[This message has been edited by pauluk (edited 12-06-2004).]