Pemmatodiscus

Probably a near relative of the Pemmatodiscus is the Kunstleria

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Pemmatodiscus gastrulaceus (Monticelli), in longitudinal section.

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Pemmatodiscus propagates asexually, by simple longitudinal cleavage; on this account it has recently been regarded as the representative of

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Pemmatodiscus (Figure 2.233, 1) is sometimes rather flat, and shaped like a hat or cone, at other times almost curved into a semi-circle.

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Pemmatodiscus and Kunstleria may be included in the family of the

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Gastraeads, that the gut remains permanently in the very simple form in which we find it transitorily in the palingenetic gastrula of the other animals; it is thus in the Gastremaria (Pemmatodiscus), the

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876

Pemmatodiscus gastrulaceus, which Monticelli discovered in the umbrella of a large medusa (Pilema pulmo) in 1895; the convex surface of this gelatinous umbrella was covered with numbers of clear vesicles, of 1/25 to 1/8 inch in diameter, in the fluid contents of which the little parasites were swimming.

The Evolution of Man — Volume 2 Ernst Heinrich Philipp August Haeckel 1876