246 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



V /L*V 



Fig. 102. — Genus Euthyroides Harmer, 1903 



A-E. Euthyroides jellyae Levinsen, 1909. A. Portion of zoarium showing the 

 interzooecial aviculariurn and two ovicelled zooecia, X40. B. The distal end of 

 a young zooecium. The frontal surface is calcified right up to the operculum, 

 X75. C. The distal end of an older zooecium in which a resorption of the lime 

 has taken place proximally to the operculum. The two hollow spines are formed 

 which cover the entrance of the compensatrix, X75. D. An operculum, X100. 

 E. An avicularian mandible, X40. (A-E, after Levinsen, 1909.) 



F-K. Euthyroides episcopalis Busk, 1852. F. A portion of a zoarium, X25. 

 (After Busk, 1852.) G. Young zooecium. The line of calcification is the line 

 x, distal to which is an accumulation of nuclei (c. s.) to which the parietal mus- 

 cles (p. m.) radiate. The distal wall (w.) of the zooecium is not completely 

 calcified; e, growing edge of the zoarium (corresponding to fig. B). H. An older 

 but much shorter zooecium, in which calcification is nearly complete. The 



