570 TRANS. ST. LOUIS ACAD. SCIENCE. 



Dendrograptus (s. g. Chaunograptus) novellus (Hall). 



(Trans. Albany Inst., vol. x.. 1S79; Geology of Indiana, 12th Rep't, 1SS2.) 



" Fossils occurring free in shales, or upon other fossil bodies, 

 in slender branching fronds. Branches diverging lax, and slen- 

 der, with numerous branchlets, both marked by numerous cel- 

 lules, which are usually indicated by the appearance of abrupt 

 expansion and contraction of the branches." 



This very small Indiana species is probably represented at 

 Hamilton, Ontario. 



Genus CALLOGRAPTUS (Hall). 



Gr. kallos; beautiful ; grapho, I write. 



(Canadian Organic Remains, Dec. ii.) 



•'Flabellate fronds, with numerous slender bifurcating branches 

 proceeding from a strong stem on axis Branches and divisions 

 celluliferous on one side, the opposite side striate; sometimes 

 distantly and irregularly united by transverse dissepiments. The 

 non-celluliferous side sometimes presents a semi-reticulate ap- 

 pearance." 



Several species of organisms occur in the Niagara rocks at 

 Hamilton which can safely be placed in this genus. As remarked 

 by Prof. Hall, the genus stands intermediate in general appear- 

 ance between Dictyonema and Dendrograptus. In Callograf- 

 tus there is no reticulate appearance, and the various bifurcat- 

 ing branches diverge from a common radicle and are free and 

 independent, unlike the arrangement in Dictyonema. Nor do 

 the branches overlie or interlace with each other as in Calypto- 

 graptus. In all the species that I have placed in this genus, 

 the branches originate in snch a manner as more nearly to re- 

 semble the outline of a bush rather than of a tree, and in some 

 cases the frond has a semicircular appearance. Some of the 

 species resemble so closely those of the Qiiebec group, that they 

 might almost be considered as varietal forms. 



Prof. Hall has remarked that some species have grown in 

 funnel-shaped ponds. I have also placed one or two species that 

 may be of that character, where the mode of branching is entirely 

 free, in this genus. It is possible that some species that have 

 been placed here might rather be placed with the genus Dendro- 

 graptus^ which this genus nearly resembles. 



