50 



THE DEVONIAN OF MISSOURI. 



cent., in thicker specimens sometimes as many as one hundred and fifty can be counted. 

 Tabulae small, flat in the centre, bent down at the edge, rendered vesiculose by the 

 introduction of cystose plates and generally somewhat disturbed in their regularity 

 by the inner ends of the septa, confined to a central zone varying in breadth from about 

 one-fourth to one-third of the entire diameter of the corallum. Vesicles filling the 

 septal interspaces outside the tabulate zone, small, strongly curved with their convex 

 sides upward, resting on each other and against the sides of the septa, their general direc- 

 tion being upward and outward at right angels to that of the arched carinae of which 

 they are independent in their disposition." 



Remarks — This species is rare in the Callaway limestone and all of the specimens 

 are imperfect. The carinae are badly weathered on the surface, and are difficult to 

 distinguish. One specimen is 6 cm. wide at the top and 15 cm. long, with both ends 

 practically complete. Another specimen of the same width is 18 cm. long, and the 

 lower end is broken away. The longitudinal section shown in figure 4 is diagrammatic. 

 It was impossible to get a section that was not highly complicated and the reticulate 

 network was filled in from a small area. The right side of the central part which shows 

 the tabulae was broken during the sectioning. The cross section shown in figure 1 

 was made from the smaller end of the specimen 18cm. long. 



Fig. 2. Sections of Cyathophyllum halli (Edwards and Haime 



1. Cross section of a long specimen, 17 centimeters from the top. No evidence 

 of spines on the septae appears. (X8/5). 



2. A small area of a vertical section which shows the complexity of the structure. 

 The right side is near the center of the specimen but is not cut to the center 

 of the tabulate area. (X 8/5.) 



3. A vertical section of a small part of a large specimen which shows the spines 

 on the septae. (X2.) 



4. Vertical section of part of the specimen shown on plate 1, figure 1. The reticu- 

 late part is somewhat diagramatic as no section was cut that did not cross 

 several septae. About two-thirds of the tabulate area is shown in the drawing. 



(X2.) 



Genus Diplophyllum Hall 



Diplophyllum callawayensis n. sp. 



Plate 3, figure 4. 



Corallum composed of nearly upright, subparallel corallites, which range up to 3 

 cm. in diameter 10 cm. from the base. Corallites straight to slightly curved, in contact 

 or separated by small interspace. Connections between corallites not observed. The 



