PLATE I. 



Fig. 1. CLISIOPHYLLUM GABBI. 



A large, somewhat weathered specimen. 



la. A calice of a smaller individual, with its margins partly broken 

 away, and the interior partly filled with stony matter, around 

 the central boss. 



1 b. Vertical section of a small specimen, showing the depth of the 



calice, and the prominence of the central boss, as well as the 

 structure of the interior. The outer vesicular zone is not 

 well seen in this specimen, which is too small to have it well 

 developed. 



Fig. 2. LlTHOSTROTION? CALIFORNIENSE. 



An external view of a part of a corallite. 



2 a. Transverse section of the same. 



"2 b. A group of three young corallites, as seen in the matrix, appa 

 rently diverging from a common base, and showing the much- 

 weathered calices. 



2 c. Longitudinal section of one of the corallites, showing the inter 



nal structure. 



Fig. 3. LlTHOSTROTION MAMILLARE 'i 



A fragment, showing the weathered lower extremities 

 of the corallites. 



3 a. Longitudinal section enlarged, showing the internal structure of 



Fig. 4. LlTHOSTROTION MAMILLARE, VUl*. 



A group of corallites. 

 4 a. Longitudinal section a little enlarged, showing the internal 



structure of one of the same. 

 4 b. Transverse section of same, enlarged. 



