A large number of representatives of the group are known from both the Old and the New World; specialization displaying itself in the later ones in the development of dermal horns over the nasal bones, either in laterally placed pairs as in some of the early forms, or in the median line, either single or double.
If the beds fall only in one direction longitudinally, their crowns should be made in the middle; but, should they fall laterally as well as longitudinally, as is usually the case, then the crowns should be made towards the upper sides, more or less according to the lateral slope of the ground.
In Cycas revoluta and C. circinalis each leaf-like carpel may produce several laterally attached ovules, but in C. Normanbyana the carpel is shorter and the ovules are reduced to two; this latter type brings us nearer to the carpels of Dioon, in which the flower has the form of a cone, and the distal end of the carpels is longer and more leaf-like than in the other genera of the Zamieae, which are characterized by shorter carpels with thick peltate heads bearing two ovules on the morphologically lower surface.
The deep valley of the Kinzig divides it laterally into halves, of which the southern, with an average elevation of 3000 ft., is the wilder and contains the loftiest peaks, which again mostly lie towards the western side.
The Silurian mica-schists of Bergen in Norway are fossiliferous; in the Alps it is believed that even Mesozoic rocks pass laterally into mica-schists and talc-schists.
In the older filters it was usual to support this sand upon small gravel resting upon larger gravel, and so on until the material was sufficiently open to pass the water laterally to underdrains.
Hilum a line; spikelets laterally compressed.
The excretory surface is increased by numerous ramified caeca which extend beneath the body wall laterally and ventrally, and open into the tube (fig.
In this suborder the head is more or less distinct, the rest of the body being in general laterally compressed and covered by a bivalved test.
Atmospheric air gains access to the air-tubes through paired spiracles or stigmata, which usually occur laterally on most of the body-segments.