614 NEW YORK STATE MUSEUM 



stages, causing a bushlilce mode of branching [pl.2, fig.13, 14, 16] is the only 

 difference which the writer can find between Clonograptus and Clemato- 

 graptus, and it is quite probable that this is of no more than subgeneric 

 importance. As, however, the latter genus has been commonly recognized 

 and comprises a small group of forms which is well characterized by the 

 feature mentioned, we will distinguish it here also though under the older 

 term Staurograptus. 



Staurograptus dichotomus Emmons 



Plate 2, figure 1-24 



Staurograptus dichotomus Emmons. Am. Geol. pt2. 1855. p.l09, pl.l, 



fig2L 

 cf. Bryograptus patens Matthew. Roy. Soc. Can. Trans, and Proc. 1893. 



v.lO, §4, p.l7, pl.7, fig.la, Ic, Id 

 Clonograptus proximatus Matthew. N. Y. A.cad. Sci. Trans. 1895. 14:265, 



pl.48, fig.la-d 

 cf. Bryograptus patens Matthew. N. Y. Acad. Sci. Trans. 1895. 14:268, 



pl.48, fig.4a, 4V 

 cf. Bryograptus lentus Matthew. N. Y. Acad. Sci. Trans. 1896. 14:270, 



pl.48, fig. 2a, 2b 

 Clonograptus proximatus Ruedemann. N. Y. State Paleontol. An. Rep't. 



1903. p.938 

 Bryograptus patens Ruedemann. Ibid. 1903. p.938 

 Bryograptus lentus Ruedemann. Ibid. 1903. p.938 



Description. Rhabdosome broadly conical to saucer shaped; mostly 



found vertically comj^ressed or spread out. Sicula short (about 1.8 mm long) 



and slender conical, suspended by means of a delicate nema, which attains 



four times the length of the sicula and has not been observed in grown 



specimens, from a chitinous disk that in diameter approximately equals 



the length of the sicula [pl.2, fig.l]. Primary thecae ("funicle") growing 



m direction of the sicula,' rhabdosome hence apparently beginning with four 



or more branches. Rhabdosome attaining a diameter of 40 mm, consisting 



of numerous (upward of 40) branches of the last order. Branches slender 



^ Figure 4c appears to me to represent an early growth stage of Dictyonema flabelliforme 



