These young persons are the Children of a Mobility said to be the finest in the universe. The scene of their existence is a place denominated the Rookery, a region situated in those obscure territories among which Oxford Street terminates. This district is very appositely named, and we are surprised that there is no corresponding neighbourhood, of an aristocratic character, denominated an Aerie. It is a place remarkable, like an actual abode of rooks, for the noisy, pugnacious, and predatory character of its inhabitants, who however, unlike those birds, are not very active in feeding their young. Their building propensities, however, are just as remarkable. Humble as they are, it cannot be denied that they have much to do in the raising of the noblest houses; and if any part of the Mobility may lay claim to heraldic honours, these, as well as the proudest landlords, are entitled to bear the "Bricklayers' Arms." Their children display a peculiarly imperfect state of costume, owing to a practice, too common among their parents, of devoting the family revenues to the purchase of a certain spirituous liquor, and of converting, for this purpose, their wardrobes into ready money; conduct highly reprehensible, since, if oppressed by _ennui_, or incommoded by the calls of appetite, they ought to have recourse to the consolations of philosophy. The Flinns, the O'Shaughnessys, and the Donovans are, as we have hinted, of Hibernian extraction. Miss Margaret Flinn was born January 10, 1824, and is now consequently in her eighteenth year. Her brother, Master Gregory Flinn, is in his ninth; his birth took place on December 28, 1832. They are the sole remaining issue of Cornelius and Mary Flinn, the remainder of whose family, amounting to ten, all died in their infancy, with the exception of their sixth son, Michael Flinn, whose afflicting death at the age of five, in St. Bartholomew's Hospital, in consequence of his clothes catching fire, was lately recorded in the journals. Miss Katherine O'Shaughnessy (born June 10, 1834) is the eldest of the seven children, the remainder of whom are males, of Judith and Terence O'Shaughnessy. It will be recollected that the late Mr. O'Shaughnessy was killed in scaling a chimney. Master Patrick Donovan is virtually an orphan, his parents, Jane and Peter Donovan, being necessitated, from some mistake with respect to property, to pass their existence in exile. He was born March 18, 1830.