DENDROID GEAPTOLITES OF HAMILTON, ONTARIO. 



15 



No additional typical forms of this species have been found. Four 

 specimens, three of which are fragmentary, furnish the basis for the 

 description of the following variety. 



CALLOGRAPTUS MINUTUS ALTUS Gurley, new variety. 



Text figure 16. 



Doctor Gurley "s description and notes are as follows: 



Polypary as couipresseil (originally?), somewhat semicircular, cousisting of 

 brancbes about 0.2 mm. in width, bifurcating 2 to 4 times in their course toward 



the periphery, set about 45-50 in 25 mm. of width, 

 ments very slender, apparently not numerous (too 

 few visible to measure distances). 



This form seems nearly allied to Spencer's C. 

 minutus, but has a larger polypary (16 mm. high). 

 Further, while agreeing fairly well with his de- 

 scription of C. minutus, it is not so easy to ap- 

 jiroxiniate it absolutely to his figure. Still it is 

 possible that with more material this variety may 

 be surpressed. 



Thecfe invisible. Dissepi- 



' Horizon and locality. — The variety is 

 based on two specimens (including the fig- 

 ured type) in the Spencer collection, from 

 the Niagara chert, Hamilton, Ontario, and 

 two additional specimens in the U. S. National Museum collections 

 Cotypes.—Cat. No. 55311, U.S.N.M. 



Figs. 16, 17. — IG, Callugkap- 



TUS MINUTUS ALTUS, NEW 



VARIETY. View of the 



HOLOTVPE ; 17, C. STKICTUS, 



NEW SPECIES. (See also 

 PL. .S, Fig. ?,.) 



CALLOGRAPTUS STRICTUS Gurley, new species. 



Text figure 17. Tlate 3, figure .3. 



This new species is based upon a single, well-preserved specimen 

 in the collection of the University of Chicago, Doctor Gurley's de- 

 scription is as follows : 



Branches straight or very slightly flexuous, 0.4-0.6 mm. wide, bifurcating at 

 frequent intervals (1 to 4 mm.) ; longitudinally striated by chitinous threads; 

 set 20-25 in 25 mm. Thecie present, flattened against the branches, but obscure; 

 apparently about 35-40 in 25 mm. Dissepiments few (at least few are pre- 

 served) and remote. 



Horizon and locality. — Niagaran (Blue Building beds of section), 

 Hamilton, Ontario. 



Holotype. — Walker Museum, University of Chicago, No. 13513. 



