QQ PROCEEDINGS OF THE NATIONAL MUSEUM vou 87 



whence budding proceeds. The zooecia are regularly 4 mm. long, 

 including the narrow proximal part, and 0.6 mm. wide at their distal 

 end. They emerge at a rather acute angle and bend slightly outward, 

 remaining free but close together throughout their course, with 3 to 

 4 in 5 mm. Branching is also rather regular at intervals of about 

 6 mm. and at an angle of 45°. 



This species shows considerable resemblance to Reptaria, differing 

 mainly in that the zooecia bud on alternate sides instead of practically 

 opposite each other. 



Occurrence.— Helderbergian (Birdsong shale) : Swaynes Mills, Benton 



County, Tenn. 

 Holotype.—V. S.TSi.M. No. 54127. 



HERNODIA DAVISI, new species 



Plate 15, Figure 9 



Nicholsonia canadensis Davis (not Hederella canadensis Nicholson), Kentucky 

 Foss. Corals, pt. 2, pi. 51, fig. 6 (not pi. 80, fig. 15, or pi. 73, figs. 10, 11), 

 1885. 



This interesting species forms featherlike incrustations upon 

 brachiopod shells, where it covers areas of several centimeters in extent. 

 Branching at intervals of 7 mm. or more and at an angle between 45° 

 and 90° prevents the zooecia from forming compact masses. Each 

 zooecial tube is distinct, curving slightly outward, and averages 2 mm. 

 in length and 0.4 mm. in width, with about 3}^ in 5 mm. Each arises 

 at an angle of 25° on alternate sides of a prolonged central tube com- 

 posed of the narrow proximal parts of the successive zooecia. 



Closely allied to H. tennesseensis in zooecial dimensions, H. davisi 

 can be distinguished by its loosely dividing branches, free tubes, and 

 more distinctly developed central tube, in the last respect showing 

 relations to Hederella. 



Our figured specimen corresponds exactly with Davis' illustration, 

 but a new name is necessary since his name Nicholsonia canadensis 

 evidently referred to Hederella canadensis Nicholson. 



Occurrence.— Middle Devonian: Falls of the Ohio (Silver Creek 

 dolomite); 2 miles north of Arkona, Ontario (Widder shale). 



Holotype.— U.S.N. M. No. 54118. 



HERNODIA T COOPERI. new species 



Plate 16, Figure 10 



This well-marked species exliibits all the generic features of Hernodia 

 except that the tubes have the thick walls and the nearly smooth 

 surface characteristic of the Auloporidae. Its generic position is, 

 therefore, doubtful, but at any rate it represents a distinct species. 



