ART. 14 CHEILOSTOMATOUS BEYOZOA CANU AND BASSKER 3 



Family ELECTRINIDAE D'Orbigny, 1851 



Genus TRETOSINA, new genus 



Greek: trctos, perforated, in allusion to the aspect of the distal portion 

 of the cryptocyst 

 The eggs are grouped in the distal portion of the zooecium and 

 escape by two small perforations or by a very narrow transverse 

 slit. The zooecia are membraniporoid with cryptocyst developed. 



Genotype. — Tretosina arcifera.^ new species. Tertiary of Australia. 

 (PI. 1, fig. 6.) 



Family HINCKSINIDAE, new family * 



We have grouped in this new family all the Membraniporae of 

 our Section II of 1920, namely, those with endozooecial ovicells. 

 It is rather probable that this family forms only a section of a 

 more extended family comprising the Flustridae and Farcimi- 

 nariidae, but as the larvae are unlniown we prefer not to make any 

 more important changes in the nomenclature. Hincksina Norman, 

 1903, Vihracellina, Memhrendoecium and Ogivalina Canu and 

 Bassler, 1917, and Setosellina Calvet, 1907, of this family are de- 

 scribed and illustrated in our work of 1920. 



The genus Gribrendoecium Canu and Bassler, 1920, is now re- 

 ferred to this family as it is derived normally from Hincksina. The 

 following new genus Aplousina also has the family characters in 

 simple form. 



Genus APLOUSINA, new genus 



Greek : aplous, simple, referring to the absence of adventitious organs 



The ovicell is endozooecial. No spines, no avicularium, no 

 dietellae. 



Genotype. — Aplousina gigantea^ new species. Gulf of Mexico. 

 (PI. 1, fig. 1.) 



Range. — Miocene — Recent. 



MemhrendoeciuTn, grandis Canu and Bassler, 1923, from the 

 American Miocene, should be classed in this new genus, which 

 differs from Merribrendoeciimh in the absence of avicularia. 



Family ALDERINIDAE, new family 



We propose this new family for all the Membraniporae in which 

 the ovicell is hyperstomial. It comprises therefore the third and 



* This family and several other new families and genera have been named but not 

 described by Canu in 1925 in his monograph with Lecointre upon the " Bryozoaires 

 Chellostomes des Faluns de Touraine et d'Angou " upon the expectation that the present 

 work, delayed in publication, would appear first. This delay has given us the oppor- 

 tunity to include the results of Doctor Harmer's work upon the Cbeilostomata of the 

 " Siboga " Expedition. 



