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amined, but in numerous specimens I have been unable to detect the slightest trace of generative structures; while on the other hand, the stomach is almost constantly more or less filled with large leucophroid bodies, which I am inclined to suspect are the reproductive bodies.”

The annexed figure of Urnatella is so strongly suggestive of the marine genus Pedicellina that I feel much tempted to place Urnatella in the sub-order Pedicellinea, in which it would then become the type of a distinct family in this sub-order. With our present imperfect knowledge of its anatomy, however, such an association would hardly be justified, and I have therefore deemed it most advisable to view it for the present as the type of a sub-order of gymnolaematous Polyzoa, premising at the same time that this location is to be considered as purely provisional.

The following Letters apply in all the Plates where they are used to

corresponding parts of the structure:

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Endocyst.

Ectocyst.

Septum of Paludicella.

Invaginated portion of the endocyst.

The proper tentacular sheath.

Mouth.

Epistome.

Orifice in lophophore forming a communication between the cavity of the epistome and the perigastric space.

CEsophagus.

Cardia.

Cardiac cavity of stomach.

Pyloric cavity of stomach.

Intestine.

Pylorus.

Anus.

Lophophore.

Tentacula.

Calyx.

Retractor muscles of polypide.

Accessory fibres of retractor.

Rotatory muscles of tentacular crown.

Tentacular muscles?

Elevator muscle of epistome.

Anterior parieto-vaginal muscles.

Posterior parieto-vaginal muscles.

Parietal muscles.

Nervous ganglion.

Nervous filament to lophophore.

Nervous filament passing round the lophophore.

Nervous filament to cesophagus.

Statoblast.

Funiculus.

Superior funiculus of Paludicella.

Hepatic layer of stomach.

Middle layer of stomach.

Internal layer of Cesophagus.

Internal layer of rectum.

External layer of stomach.

External layer of oesophagus.

External layer of rectum.

Spermatozoa.

Gemma.

Testis.

Ovary.

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