DENDROID GRAPTOLITES OF HAMILTON, ONTARIO. 



35 



sometimes extremely and often nndnlnte or more or less tortnons, and really or 

 apparently fusing Desmograptus fashion. In places where the meshwork is 

 laid down evenly and without distortion there are about .30 branches in 25 

 mm. of width. Proximally the number may perhaps be somewhat less (say 27). 

 Distally, especially laterally, where the branches are reflexed, and, in some 

 places crowded, there may be 35 in 25 mm., a condition perhaps due to distortion. 

 The interspaces then are, in general, narrower than the branches, and much 

 narrower distero-laterally, where the latter are crowded. The dissepiments 

 are heavy (0.2-0.4 mm. thick), and apparently somewhat remote, but the exact 

 42 



Figs. 41-43. — Dictyoxema desmoides^ new species. 41, The holotype, a small but 



KATHER COMPLETE RHABDOSOME. ( BT R. R."BASSLER.) (SEE ALSO PL. 4, FIG. 3) ; 42, 



43, Paratypes. Two fragmentary rhabdosomes. 



distance cannot be stated. Meshes rectangular, elliptic, or irregular. Thecse 

 obscure, but apparently about 50 in 25 mm. 



Horizon and locality. — Niagara chert, Hamilton, Ontario. 

 Holotype. — New York State Museum, Albany, New York. 

 Parahjpe.—Cat. No. 5.5304, T^S.N.M. 



DICTYONEMA PERCRASSUS Gurley. new species. 



Doctor Gurley 's description is as follows: 



Portion of the polypary seen (incomplete proximally) flabellate. radiating 



rather rapidly, the width increasing, in one 

 specimen, in the longitudinal or radial dis- 

 tance of 30 mm. from 8.5 to 38 mm. and the 

 branches from 7 to 21. The width thus in- 

 creases more rapidly than the branches. The 

 increased space is, however, taken up by the 

 increased thickness of the branches, which, 

 in proceeding from the base, rapidly increase 

 to a width of about 0.8 mm. and at the 

 periphery may reach 1 mm. Proximally a 

 few are as narrow as 0.4 mm., but nearly 



Fig. 44.— Dictyoxema percrassos, ^'^^ '^^'^ ^'^ °^™-' ^^^ ^^me measure 0.6 mm. 

 A FRAGMENTARY Distally the interspaces are quite or very 

 nearly as wide as the branches, but never 

 wider. Proximally, however, they are about IJ times as wide as the branches 

 or (with the narrowest branches) even a little more. Proximally the number 



x'Ew species. 



RHABDOSOME. 



