With the exception of the three doubtful species mentioned above, the list of species of Thalassema is as follows:—

Th. neptuni Gaertner (Fig. 224). English Channel (Devonshire coast), Concarneau, Mediterranean (Gulf of Marseilles), Irish coast (Dungarvan).

Th. gigas Max Müller. Trieste.

Th. vegrande Lampert. Philippine Islands.

Th. baronii Greef. Canary Islands (Lanzarote).

Th. formosulum Lampert. Shanghai and Philippine Islands.

Th. exilii Fr. Müller. Brazil (Desterro).

Th. moebii Greef. Mauritius.

Th. erythrogrammon Max Müller. Red Sea and East Indies (Billiton).

Th. caudex Lampert. Red Sea and Indian Ocean.