Disconectae form a special group among the Siphonophorae; they are distinguished from other Cnidaria of this peculiar subclass, Siphonanthae, by the medusa-shaped colony forming a flat disc; on its lower side numerous and diverse individuals of the animal colony are fixed to it. All Disconectae swim at the surface of the open ocean, often in huge clusters; among the biggest species the umbrella reaches a diameter of a thaler coin. Most species are distinguished by a magnificent blue colouration; stomach and Gonophorae are usually coloured in red or yellow. All specimen of this plate are slightly enlarged.
In all other Siphonophorae, the Siphonanthae (so in Cystonectae illustrated in plate 7), the central shaft of the Cormus, out of which individual animals sprout that are differentiated by the tasks they perform, is formed by the vertical stomach tube of the initial ‘medusa mother’; here however, in the Cystonectae (or Disconanthae) with the help of their horizontal umbrella. In the centre of their lower base (fig. 6, 8, 9) the eight-loped mouth becomes visible at the lower end of the hanging central stomach (fig. 1, 4, 7). It is surrounded by a ring of Gonophorae (‘sexual animals’). Further outward along the rim of the umbrella stands a corona of ‘capturing threads’ or tentacles, armored with circular ‘nettle buds’ (fig. 1, 5, 8). In the upper part of the centre of the umbrella lies enclosed a circular, yellowish ‘swimming bubble’ filled with air (fig. 3 and 5).
Translation of the original German introduction by Ernst Haeckel:
Phylum of Cnidaria (Nesseltiere); - subclass of Siphonophorae (Staatsquallen); - order of Disconectae (Schildquallen).
Translation by VR Translators Bangalore
This is one of the 100 pop science biology illustrations that were published from 1899 – 1904 in Leipzig by Ernst Haeckel through Verlag des Bibliographischen Instituts.