CORALS OF THE CINCINNATI GROUP. 219 



5. Length one inch ; diameter at summit nine lines ; ninety-six septa, 

 alternately large and small. 



6. Length fourteen lines; diameter at summit nine lines; ninety 

 septa, alternately large and small. 



7. Length six lines ; diameter at summit four and a half lines ; septa 

 thirty, all equal in size and extending to the center. This would appear 

 to the form described by Hall under the name of S. parvula, and I do not 

 feel sure whether it is the young of S. corniculum or really a distinct 

 species. 



The average number of septa in a tj'pical example of S. corniculum 

 would appear to be one hunred and twenty, or thereabouts. Hall gives 

 the number at sixty, but in this enumeration he appears to have neg- 

 lected the smaller secondary septa. Prof. Hall, however, gives one hun- 

 dred and twenty as the number of the septa in his S. multilamellosa, 

 which would seem to be probably only a variety of S. corniculum. 



Position and locality : Upper beds of Cincinnati group, Waynesville, Lebanon, Ox- 

 ford, etc., Ohio. 



Genus PAL^OPHYLLUM, Billings, 1857. 



(Gaol. Survey of Canada, Report of Progress, 1857, p. 168.) 



" Corallum fasciculate or aggregate ; corallites surrounded by a thick 

 wall ; radiating septa extending the whole length ; transverse dia- 

 phragms either none or rudimentary ; increase by lateral budding. This 

 genus only differs from Petraia or Streptelasmn, by forming long fasciculate 

 or aggregate masses, instead of being simple." (Billings, loc. cit.) 



Amongst the numerous specimens from the Cincinnati group kindly 

 submitted to me by Mr. U. P. James are several which agree with Strep- 

 telasma corniculum, Hall, in most respects, but differ in the fact that they 

 produce lateral buds, or sometimes appear to divide fissiparously. They 

 do not form large colonies, but usually consist of from two to six or 

 seven corallites. They do not thus constitute "fasciculate or aggregate 

 masses " ; but I have thought it advisable to refer them provisionally to 

 this genus, rather than to form a new genus for their reception upon in- 

 sufficient material. 



