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NEW YORK STATE MUSEUM 



reason for suspecting the validity of the generic reference of the species. 

 May it not then be possible that, compelled as we are for the most part to 

 deal with and to base our. species upon fragments of the meshwork, we are 

 confounding two series ; say for illustration * a series lower Ordovician 

 (Calciferous) in distribution, and a series Upper Silurian (Niagara) in dis- 

 tribution, both series agreeing in type of meshwork (probably a character 

 of subordinate biologic value), but differing in characters of the base? At 

 present there is nothing to negative such a view. Until we know the prox- 

 imal portion of the type species (C . salteri) this reasoning must of 



course remain purely a possibility. But 

 in a review like the present, a clear 

 outlining of future possibilities ma) - be 

 justifiable. Certainly only under some 

 such condition, it seems to me, would 

 Odontocaulis stand much chance of ulti- 

 mate retention. Its provisional reten- 

 tion, I think advisable, pending a fuller 

 knowledge of the condition cf the base 

 in the remaining Niagara Callograptiis 

 species. At present its most distinctive 

 characters seem to be : Polypary arising 

 from a single stem which is expanded 

 proximally into a "dish," and is theca- 

 phorons along one side ; distal branches 

 more or less connected by dissepiments. 



Odontocaulis hepaticus sp. nov. 



Plate I, figures 6, 7 



Description. Rhabdosome of small 

 or moderate size (65+ mm), consisting 

 of a deeply lobate basal disk (5 mm), 

 Kofe"f™ of Se'hS^" Enlargement of portions short but stout theciferous stem and 

 the probably infundibuliform frond. Branches frequently bifurcating, the 

 resulting branches little diverging, closely arranged, of rigid appearance, 

 nearly straight, with an average width of .3 rara-,5 mm, not connected 

 by dissepiments. Thecae perspicuous with acute denticles, inclined 30 to 

 axis of branch, numbering 14-15 in 10 mm; ventral margin straight or 



Fig. 79-81 Odontocaulis hepaticus sp. nov 

 Fig. 79 Enlargement (x 6) of basal portion of type speci 

 men. The transverse lines represent cracks in the thick 



* For illustration only, and as a pure surmise of the possibilities of the case. 



