SYSTEMATIC DESCRIPTIONS 



Order CHEILOSTOMATA Busk 



Suborder ANASCA Levinsen 



Division 1. INOVICELLATA Jullien, 1888 



Family AETEIDAE Smitt, 1867 



Descriptions and illustrations of the structure of this family and 

 its single genus Aetea were given in our monograph of 1920, to which 

 the reader is referred for details. A more extended discussion of the 

 family, the genus Aetea and two species, A. anguina Linnaeus, 1758, 

 and A. truncata Landsborough, 1852, is given in the Report on the 

 Polyzoa of the Siboga Expedition, 1926, by Doctor Harmer, who notes 

 the significance of the ctenostomatous characters in these species and 

 refers the group to Jullien's division Inovicellata. 



Division 2. MALACOSTEGA Levinsen, 1909 

 Family EUCRATIIDAE Hincks, 1880 



The fertile zooecia are gonoecia (deprived of polypide with ten 

 tacles). The zooecia expand from the base upwards, with a terminal 

 oblique opesium.' Avicularia and vibracula are wanting. The zoarium 

 is flexible and nonarticulated. 



Special larva in which the terminal bud is much reduced, the aboral 

 face is very much developed, the oral face is completely flat and the 

 stomach trilobate. It forms a transition toward the Cyphonautes 

 form. The zooecia are club-shaped. The zoarium is radicellate. 

 The ancestrula is of a special type. 



As noted by Harmer "The family is characterized by the erect, 

 frequently uniserial, habit of its members, by the tendency of the 

 zooecia to have a tubular form (perhaps a primitive feature) and by 

 the correlated restriction of the opesia to a part of the frontal surface." 



Hincks, 1880 classed in this family the following genera: 



Eucratea Lamouroux, 1812; Gemellaria Savigny, 1811; Scrwparia 

 Hincks, 1880; Brettia Dyster, 1858, and Huxleya Dyster, 1858. 



The genera Gemellaria, Corynoporella and Brettia are deprived of 



ovicells and we classify them in the family Gcmellariidae Busk, 



1859, to which we give a more restricted and exact meaning. The 



structure of Huxleya is not known and it is impossible to classify it; 



perhaps it will prove to belong to the Catenariidae. 



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