The Transactions of the Cardiff Naturalists' Society is online to view. I have been reading Howard Hallett's original Lepidoptera of Glamorgan, which is in Vol. L, 1917 p45. That article and Hallett's annotated notebooks, which contain other records not published in the original article, were the basis from which all our historical records come from. Hallett edited the Entomological Notes until 1936 and again briefly in the late 40s until 1952. He died in 1958.
L = 50.
The link: welshjournals.llgc.org.uk