The kind of door to which these mouldings belong, is shown, with the other groups of doors, in Plate XIV. Vol. II. fig. 6 _a_. Then 6 _b_, 6 _c_, 6 _d_ represent the groups of doors in which the Byzantine influence remained energetic, admitting slowly the forms of the pointed Gothic; 7 _a_, with the gable above, is the intermediate group between the Byzantine and Gothic schools; 7 _b_, 7 _c_, 7 _d_, 7 _e_ are the advanced guards of the Gothic and Lombardic invasions, representative of a large number of thirteenth century arcades and doors. Observe that 6 _d_ is shown to be of a late school by its finial, and 6 _e_ of the latest school by its finial, complete ogee arch (instead of round or pointed), and abandonment of the lintel. These examples, with the exception of 6 _a_, which is a general form, are all actually existing doors; namely: 6 _b._ In the Fondamenta Venier, near St. Maria della Salute. 6 _c._ In the Calle delle Botteri, between the Rialto and San Cassan. 6 _d._ Main door of San Gregorio. 6 _e._ Door of a palace in Rio San Paternian. 7 _a._ Door of a small courtyard near house of Marco Polo. 7 _b._ Arcade in narrow canal, at the side of Casa Barbaro. 7 _c._ At the turn of the canal, close to the Ponte dell' Angelo. 7 _d._ In Rio San Paternian (a ruinous house). 7 _e._ At the turn of the canal on which the Sotto Portico della Stua opens, near San Zaccaria. If the reader will take a magnifying glass to the figure 6 _d_, he will see that its square ornaments, of which, in the real door, each contains a rose, diminish to the apex of the arch; a very interesting and characteristic circumstance, showing the subtle feeling of the Gothic builders. They must needs diminish the ornamentation, in order to sympathize with the delicacy of the point of the arch. The magnifying glass will also show the Bondumieri shield in No. 7 _d_, and the Leze shield in No. 7 _e_, both introduced on the keystones in the grand early manner. The mouldings of these various doors will be noticed under the head Archivolt. [Illustration: Plate VI. BYZANTINE JAMBS.] Now, throughout the city we find a number of doors resembling the square doors of St. Mark, and occurring with rare exceptions either in buildings of the Byzantine period, or imbedded in restored houses; never, in a single instance, forming a connected portion of any late building; and they therefore furnish a most important piece of evidence, wherever they are part of the original structure of a _Gothic_ building, that such building is one of the advanced guards of the Gothic school, and belongs to its earliest period. On Plate VI., opposite, are assembled all the important examples I could find in Venice of these mouldings. The reader will see at a glance their peculiar character, and unmistakable likeness to each other. The following are the references: