In their typical state of development, the first maxillae offer a striking contrast to the mandibles, being composed of a two-segmented basal piece (cardo and stipes, fig.
Croce outside the Roman town, which formed a rectangle of about 400 by 600 yds., with four gates, the Decumanus being represented by the Via Strozzi and Via del Corso, and the Cardo by the Via Calcinara, while the Mercato Vecchio occupied the site of the Forum.
E, First maxilla; a, cardo; b, stipes; c, galea; d, lacinia; e, palp. B, Second maxillae (Labium); a, mentum; b, ligula (between the two galeae); c, c, palps.
It is remarkable as being contrary to Roman surveyors' practice, according to which the basis of division is the intersection at right angles of the cardo and decumanus, which would give an even (not an odd) number of smaller squares.
Another exception is to be found in the Strada Stabiana (Stabian Street) or Cardo, which, owing to the existence of a natural depression which affects also the line of the street just east of it, is not parallel to the other north and south streets.
This is seen especially in the case of the street from the Porta Ercolanese to the forum and the Strada Stabiana (or Cardo), both of which were among the most frequented thoroughfares.