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BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



simply to render a little more intelligible the descriptions of the very 

 mediocre classificator, Oken. We adopt the principle of least change 

 based on long usage. It will always be very difficult to harmonize 

 the ancient authors, ignorant of the structure of the bryozoa, with the 

 precision and exactness of modern science. 



Fig. 2. — Genus Eucratea^ Lamouroux, 1812 



A-C. Eucratea chelata Linnaeus 1758. A. Zoarium natural size. B. Zoarial 

 fragment with its radicells, X 24. The basal edge of the distal wall is not angular, 

 the ovicelled zooecia are attached either proximally to the frontal area or to the 

 basal surface of other zooecia (after Milne Edwards). C. Ovicelled zooecium; 

 it is of smaller size, X25 (after Levinsen, 1894). 



Fig. 3. — Genus Scruparia Hincks, 1857 



D-G. Scruparia clavata Hincks, 1880. D. Biserial form with ovicelled 

 zooecia, X50. E. Basal side of biserial form, X50. F. Uniserial form, X50. 

 G. Group showing the mode of branching, X50. (A-D, after Hincks, 1SS0.) 



Family GEMELLARIIDAE Busk, 1859 



The zoarium is flexible, radiccllcd. The zooecia are club-shaped, 

 with a large gymnocyst. No ovicell. Larva unknown. 



Genus GEMELLARIA Van Beneden, 1845 



The zooecia are in pairs back to back. The basal edge of the distal 

 wall is angular. The radical fibers issue from the lateral margin in 

 the proximal part of the zooecium. 12-14 tentacles. 



Genotype. — Gemellaria (Sertularia) loricata Linnaeus, 1758. Recent. 



