58 



BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



Genus EUCRATEA Lamouroux, 1812 (Hincks, 1880). 



The zooecia are sub-calcareous, rising immediately one from the 

 other, so as to form a single series. The branches are given off from 

 the front of a cell below the opesium. The zooecia have" a large 

 gymnocyst. The tentacular sheath terminates above in a ring of 

 setae. The gonoecia have an endozooecial ovicell. 10-12 tentacles. 



creeping branch — 

 radicle 



opesium and cctoryst 



—young zooccium 



opercular valve 



Fig. 1. — Family Eucratiidae Hincks, 18S0 



Genotype. — Eucratea (Sertularia) cJielata Linnaeus, 1758. Recent. 



Harmer, 1923, by studying the old texts established that Gemellaria 

 Van Beneden, 1845, is a synonym of Eucratea Lamouroux, 1912, and 

 that Sertularia chelata Linnaeus, 1758, which has usually been regarded 

 as the genotype of Eucratea, has no claim to this position. 



