306. _Cicada or Tettigonia Septemdecim._--In Latrobe's _Rambler in North America_, London, 1835, vol. ii. p. 290., is a curious account of this insect, which visits Pennsylvania every seventeenth year, and appears about May 24. It is under an inch in length when it first appears early in the morning, and gains its strength after the sun has risen. These insects live ten or fifteen days, and never seem to eat any food. They come in swarms, and birds, pigs, and poultry fatten on them. The female lays her eggs in the outermost twigs of the forest; these die and drop on the ground. The eggs give birth to a number of small grubs, which are thus enabled to attain the mould without injury, and in it they disappear; they are forgotten till seventeen years pass, and then the memory of them returns, and they rise from the earth, piercing their way through the matted sod, the hard trampled clay, &c. They appeared in 1749, &c., to 1834, and are expected in 1851. Has this expectation been fulfilled? C. I. R. 307. _The British Sidanen._--Under this title (the proper spelling in which should be _Sina_ or _Senena_) an article appears in Vol. iv., p. 120., comprising a portion of the genealogy of the Welsh princess, in which three of her sons are mentioned, viz., Owen, Llewellyn, and David. But there was a _fourth_ son, Roderic, who settled in England, and appears to have been residing there for some time, when the fatal rupture occurred between the two countries. It would appear that descendants of his have lived, and are living in our own times; among them, the late Dr. John Mawer, of Middleton Tyas, whose remarkable epitaph was given in a former number of "NOTES AND QUERIES." My first inquiry is, Is there known to exist any genealogy assuming to extend between the Rev. and learned gentleman just named and Prince Roderic? I am told there was one published in the _British Peerage for 1706_, at which time John Mawer would be three years of age; is such the fact? I wish also to ask, whether Prince _Owen_ was in existence at the time of the deaths of Llewellyn and David--whether in Wales or England? and whether he was the ancestor of Owen Tudor, the proud father of Henry VII.; and, if not, who _was_ Owen Tudor's ancestor? AMANUENSIS. 308. _Jenings or Jennings._--Was the late Mr. Jenings of Acton Hall, Suffolk, descended from the family of Jenings, formerly of Silsden, Skipton in Craven, and afterwards of Ripon, Yorkshire; and if so, where can information as to the pedigree be obtained? A. B. C. Brighton. 309. _Caleva Atrebatum, Site of._--May not the site of Caleva Atrebatum have been at Caversham, on the north of the Thames, near Reading? The distance of Caleva from Londinium was forty-four Roman miles, making forty English; and from Venta Belgarum, thirty-six Roman or thirty-three English miles.