y8 Cincinnati Society of Natural History. 



FiSTULiPORA FLABELLATA, D. sp. (Plate VII., figs. 2H, 26a, 26/>. ) 



[T^iy-— From flabellinn, a fan.j 



Pol^'zoaiy forming irreoular, fan-like expansions, carrying cell 

 mouths on both sides. Thickness usually A^arying from one to two 

 lines. Surface sometimes raised into broad and inconspicuous monti- 

 cules, carrj'ing tubules of the ordinary size. Cells oval, with apertures 

 a little arched, arranged in bent and rather irregular rows; about five 

 cells occupying the space of one line, the distance between them being 

 equal to a little more than their diameter. 



lutertubular space occupied by a great number of minute cells, 

 which are nearly equall}^ distributed between all the tubes of larger or 

 ordinary size. 



Longitudial sections show the tubules to be nearh^ vertical in the 

 middle of the polyzoary, and then gradualh' bending outwards to the 

 surface. Tabulae are veiy sparingl}' developed, These sections clearly- 

 demonstrate that the interstitial tubuli observed on the surface, are 

 not of the nature of a coeueuchyma, but are only aborted cells. They 

 are developed only near the surface. In the central portion of a trans- 

 verse section, the tubes are angular, of unequal size and irregular form, 

 with no minute tubuli between them. 



Formation and locality : this species is found quite common at a 

 height of 400 feet above low water mark, in the Ohio Hiver, at the 

 (juarries back of Cincinnati, O. 



Inocaulis arbuscula, n. sp. (Plate VII., figs. 27, '21 a.) 



[Eiiy .—Arbustiula, a little shrub.] 



Frond smalj, originating in a single stripe at the base, diffusely 

 branched and spreading above; branches narrow, and varying some- 

 what in width, the strongest not exceeding two hundredths of an inch, 

 with strong, projecting, prong-like processes rising from the sides at 

 frequent, but variable intervals; bifurcations numerous, not at equal 

 distances. Substance of the frond thin, carbonaceous ; the surface is 

 marked with faint, longitudinal, or slightly diverging corrugations, ir- 

 regularly distributed over most parts of the branches ; the free ex- 

 tremities of the branches are usually pointed. 



The surface corrugations on this species are much like those seen 

 on some species of Dictyonema, but the mode of growth and the entire 

 absence of connecting filaments, will at once distinguish it from species 

 of that genus. Inocaulis bella, Hall and Whitfield, from the Niagara 

 Group, is closely related to this form ; that species is, however, more 



