The remaining two families of Enteropneusta, Ptychoderidae and Spengelidae, contain species of which probably all pursue an indirect course of development, culminating in a metamorphosis by which the adult form is attained.
The Jurjura range, extending through Kabylia from Algiers to Bougie, contains the peaks of Lalla Kedija (7542 ft.), the culminating point of the maritime chains, and Babor (6447 ft.).
In area and nearly triangular in form, composed of conical hills, culminating in Paradise Peak (1920 ft.).
Under these circumstances the Bolshevist advance reached its culminating point in May 1919, when the Soviet armies occupied Telshi and Shavli in the north and Olita in the south, thus threatening Kovno itself.
To the south of the Kinzig the mean height is 3100 ft., and the loftiest summit, the Feldberg, reaches about 4898 ft., while to the north the mean height is only 2100 ft., and the Belchen, the culminating point of the whole, does not exceed 4480 ft.