288 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vOL. 45 



Occun-cnce. — Hamilton formation, Eighteen Mile creek and other 

 localities in New York; Thedford (Widder) and neighboring locali- 

 ties in Ontario. 



Cat. No. 43,137, U. S. N. M. 



ASCODICTYON FLOREALE new species 



(Platk LXVIII, 13) 



Though easily distinguished from A. stcllatitni, this species differs 

 in little or nothing save that it is considerably smaller. The aver- 

 age width of the flower-like clusters is only about 0.5 mm. while in 

 A. stellatum they usually reach a diameter of nearly i.o mm. The 

 clusters occur also at shorter intervals in A. florealc, the average dis- 

 tance from center to center being less than i.o mm. With specimens 

 in hand these differences cannot fail to strike the observer at once. 



Occurrence. — Hamilton formation, 2 miles west of Alpena, ]\Iich- 

 igan. 



Cat. No. 43,136, U. S. N. M.- 



ASCODICTYON PARVULUM new species 



(Plate LXVIII, 14) 



This species is characterized by its extreme minuteness and 

 crowded habit of growth. Five to eight vesicles occur in each clus- 

 ter, but in parts of the colonies they appear to be arranged without 

 regard to any central point or points. As a rule these irregularly 

 disposed vesicles are of less than the average size. Generally the 

 clusters are less than 0.5 mm. apart, measuring from center to center. 

 The vesicles are elliptical or pyriform in outline, and vary in length 

 from 0.07 mm. to 0.12 mm. 



Occurrence. — Chester group, Jackson county, Kentucky. 



Cat. No. 43,143, U. S. N. M. 



ASCODICTYON FILIFORME Vine 



(Not figured) 

 1882. Ascodictyon iiliforme Vine, Quart. Jour. Geol. Soc. London, 



XXXVIII, pp. 54-55. 

 1894. Ascodictyon iiliforme Vine, Ann. & Mag. Nat. Hist., sen 5, xiv, 



pp. 78-80. 

 1887. Ascodictyon iiliforme Vine, Proc. Yorkshire Geol. & Polyt. Soc, 



IX, p. 183, pi. 12, figs. 1-4. 

 1892. Ascodictyon iiliforme Vine, Ibid., xii, p. 86, pi. iii, figs. 8-15. 



Vesicles not occurring in regular clusters, as in the more typical 

 species of the genus, but developed at very unequal though generally 

 short intervals from the sides of the connecting threads ; occasionally 



