| III. Ommacampida. 1. Cortical shell simple. (Medullary shell double.) |  | Without polar tubes, | 169. Ommatocampe. |
| With two hollow fenestrated tubes, on the poles of the axis, | 170. Ommatartus. | ||
| III. Desmocampida. 2. Cortical shell double. (Medullary shell double.) | | Without polar tubes, | 171. Desmocampe. |
| With two hollow fenestrated tubes, on the poles of the axis, | 172. Desmartus. | ||
| III. Zygocampida. 3. Cortical shell triple. (Medullary shell double.) | | Without polar tubes, | 173. Zygocampe. |
| With two hollow fenestrated tubes, on the poles of the axis, | 174. Zygartus. |
| I. Ommacampida. 1. Cortical shell simple. (Medullary shell double.) | ||||
| Without polar tubes, | ||||
| 169. Ommatocampe. | ||||
| With two hollow fenestrated tubes on the poles of the axis, | ||||
| 170. Ommatartus. | ||||
| II. Desmocampida. 2. Cortical shell double. (Medullary shell double.) | ||||
| Without polar tubes, | ||||
| 171. Desmocampe. | ||||
| With two hollow fenestrated tubes on the poles of the axis, | ||||
| 172. Desmartus. | ||||
| III. Zygocampida. 3. Cortical shell triple. (Medullary shell double.) | ||||
| Without polar tubes, | ||||
| 173. Zygocampe. | ||||
| With two hollow fenestrated tubes on the poles of the axis, | ||||
| 174. Zygartus. | ||||
Genus 169. Ommatocampe,[[208]] Ehrenberg, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 832.
Definition.—Zygartida with simple cortical shell and double medullary shell, without polar tubes.
The genus Ommatocampe was founded by Ehrenberg in 1860 for one of his "Haliommatina," with the following diagnosis:—"Shell rod-like, long, articulate, with nucleus, without spines, with four or more joints." The species figured by him, Ommatocampe polyarthra, exhibits five pairs of chambers on both sides of the meridian plane of the cortical shell, the centre of which includes a double medullary shell. It represents the most simple form of all Zygartida, and may be derived phylogenetically from Cyphonium simply by multiplication of the chambers of the cortical shell, growing on both poles of the main axis.
Subgenus 1. Ommatocampium.
Definition.—Surface of the cortical shell smooth or rough, without thorns or spines, also without polar spines.
1. Ommatocampe polyarthra, Ehrenberg.
Ommatocampe polyarthra, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 279, Taf. vi. fig. 9.
Cortical shell with smooth surface, composed of six to ten chambers of the same size and form. Every chamber kidney-shaped, about twice as broad as long, with three transverse rows of circular, subregular pores, twice to three times as broad as the bars. Both medullary shells spherical.