These Capella lugs , as David says, are very common on many Raleighs from the early to mid 1970s.. I at first thought it was a special Raleigh design as my imaginative artist's eye saw a Heron head viewed from the top...The point of the lug being a bird's beak and with the two circular "eyes" on each side. Made perfect sense to me!
Only in the past few years have I learned through reading my stash of old Cycling (weeklies) that these lugs were designed and premiered with a fair amount of hoopla by Carlton in the early 1960s, before the Raleigh takeover. There must a have been a serious pile of these Capella lugs made as Raleigh was not hesitant to reach in that box-o-lugs on many occasions for nearly 20 years thereafter.
Dale Brown