Two leading types may be distinguished amongst the Graptolites, which are termed respectively monoprionidian and diprionidian. The monoprionidian Graptolites, such as Monograptiis priodon (fig. 54), are distinguished by the fact that the polypary, whether simple or branched, possesses but a single row of cellules or hydrothecæ. In the diprionidian forms, on the other hand, as in Diplograptus (fig. 63), the polypary possesses a row of cellules on each side.

joyful excursionings

Coordinate term: annellide

As your pitcher drives down the mound, his plant foot should be on the same line as his back foot.