CGELENTERATA. 



HYDKOZOA. 



Family Dictyonemidje. 



Dictyonema, Hall, 1852, 



DiOTYONEMA CRASSUM, Sp. nOV. 

 Plate IV, figures 1, 2. 



Shape of entire frond not known. The largest fragment 

 measures 7.5 by 7.5 cm. The branches are marked by coarse 

 longitudinal striae, or wrinkles, which are not continuous. The 

 dissepiments are nearly equal in size and parallel in direction, 

 forming with the branches a rather uniform reticulation. Both 

 branches and dissepiments are enlarged at their point of union, 

 giving the fenestrules a more or less rounded form. Thickness 

 of branches, .5 to 1 mm. Dissepiments of about the same size. 

 The specimens examined are casts. 



The zoarium in Dictyonema crassum is coarser than in D. reti- 

 forme, Hall, of the IN'iagara group, the dissepiments heavier, and 

 the fenestrules more rounded. 



The quality of the material would hardly warrant the descrip- 

 tion of a new species, were it not that this is the first appearance 

 of the genus noted in Lov^er Helderberg strata. 



Horizon. — Shaly limestone. 



Locality. — Clarksville, Albany county, New York. 



Family Monoprionid^. 

 Monograptus, Emmons, 1856. 



MONOGRAPTUS BEECeERI, Sp. UOV. 



Plate IV, figures 3-15. 



Stipe linear, minute, with a carination on either side. Surface 



marked by fine longitudinal striae, which are not continuous. 



Denticulations about the same width as the stipe, acute, distant. 



It is not known whether the stipe is simple or branched. 



This species of Monograptus is interesting, not alone as the 

 first example of the genus reported from the Lower Helderberg 

 rocks, but also as the last known representative of this character- 



