REPORT OF THE STATE PALEONTOLOGIST I9O3 237 



mural pores are on the lateral faces of the cells and about midway 

 between the tabulae. The tabulae are thus as numerous as in 

 F. helderbergiae. The corallum is lenticular in shape, and 

 accordingly the only difference between the two species is in the 

 shape of the corallum.^ It was only in the Favosites bed that the 

 shape of the corallum was observable and this only in cross section. 

 Here the corallum usually gives, at right angles to the bedding plane, 

 a round or elongate cross section with the corallites growing in all 

 directions from a central point. A few, however, were noticed which 

 had a semicircular cross section with the flat portion lying on the 

 bedding plane and the corallites growing from the center of the flat 

 portion. It seems, then, that we have the lenticular, the hemis- 

 pheric, as well as the spheric shaped corallums in this 3 foot Favo- 

 sites bed. 



It seems to be a question worth considering whether two dis- 

 tinct species should be based wholly on the form of the colonies of 

 which the individuals are exactly alike. Might not the shape of the 

 colonies be determined by the varying conditions of growth ?^' ^ 



Favosites sphaericus Hall 



Found from the Upper Manlius to the Lower New Scotland 

 inclusive, being specially abundant in the Favosites bed. One speci- 

 men from the Coeymans measured 12mm in length by lomm in 

 width ; the tubes averaged a diameter of .3mm with a few as wide 

 as .5mm. The angles of the walls were quite nodose. On one 

 specimen from the Upper Manlius the tubes averaged about .2mm 

 in diameter, while the corallum was 5mm long by 3mm wide at the 



^After this determination was made, it was found that Lambe had reached 

 a similar conclusion four years previously, 



Contrib. Can. Pal. v.4, pt i, 1899, p.7. 



^F. niagarensis was established by Hall in 1852. Pal. N. Y. 2:125. 

 F. helderbergiae was established by Hall in 1874. N. Y. State Mus. 

 Nat. Hist. 26th Rep't. p.m. 



'Girty concludes from a study of F. helderbergiae and F. 

 c o n i c u s Hall from the Helderberg of Albany county, N. Y., that both 

 may refer to the same organism at different stages of growth and preserva- 

 tion. Girty, G. H. A Revision of the Sponges and Coelenterates of the 

 Lower Helderberg Group of New York. N. Y. State Mus. 48th An. Rep't. 

 1894. pt 2. 



