for ambulatories; whereas in the usual simple peristyle, where the space between the outer columns and the walls of the cella was limited to the width of a single intercolumn, the side colonnades were mere narrow passages, very little wider—at least in Doric temples—than the diameter of the columns themselves, consequently of very little actual service. In what is called the _pseudo-dipteral_ mode, more of clear space within the colonnades was provided by omitting the inner columns, which mode reduced the plan to that of a simple peristyle, the only difference being, that instead of the width of a single intercolumn, a clear space, equal to two intercolumns and one column, was gained for the ambulatories. The Temple of Jupiter at Selinus was of this description, and being only octastyle in front,—the least possible width for a dipteral or pseudo-dipteral plan,—of the seven front intercolumns, four (_i. e._ two on each side) were given to the lateral colonnades, and only three left for the breadth of the _cella_, which must have looked like a smaller edifice standing within a colonnaded and covered enclosure. [5] By way of illustrating these terms more directly by instances taken from well-known modern porticoes which answer to the respective denominations and distinctions above noted, we here give a classified list of some of them: Distyle { Two columns } St. Paul’s, Covent Garden. in antis. { & two antæ. } Three } inter- { Hanover Chapel, Regent Street. Tetrastyle. Four columns. } columns. { *Covent Garden Theatre. { St. George’s Church, { Bloomsbury. { *St. George’s, Hanover Square. { St. Martin’s Church. { Five { *St. Pancras’ Church. Hexastyle. Six columns. { inter- { India House. { columns. { Post Office. { *College of Surgeons. { *College of Physicians. { *Colosseum. { Seven { National Gallery. Octastyle. Eight columns. { inter- { Royal Exchange. { columns. { British Museum. { Nine } Decastyle. Ten columns. { inter- } London University College. { columns. } The porticoes marked with the * are simple prostyles, or _monoprostyle_, advancing only a single intercolumn forwarder than the rest of the building; while the others are _diprostyle_, or show two open intercolumns on their flanks; except Hanover Chapel, whose portico is partly prostyle and partly recessed, and that of the India House, which is entirely recessed, although its elevation is not a composition _in antis_; had it been such, it would have been a _tetrastyle in antis_, that and a hexastyle having the same number of intercolumns, viz. five.