68 Citicinnati Society of jVahtra/ History. 



the bifurcation thickens towards the end, and is two-fifths 

 wider at the bifurcation than where it starts from the body. 



"Prominent tubercles, from 's to ]/x of an inch above the 

 general surface, from X to ^2 an inch broad at their bases, and 

 from ^ to >2 an inch apart at the bases, are distributed irreg- 

 ularly over the surface of the body and arms, also a few pit- 

 like cavities of irregular shapes. One side has, evidently, 

 been expo.sed to the weather and action of water for some 

 length of time, and become somewhat worn away ; on the 

 worn portion the tubercles are all removed. The general .sur- 

 face of the fo.ssil is rough, but with a good magnifier it is 

 difficult to determine whether the roughness may have been 

 cau.sed by pores ; the appearance resembles fine papillae, but 

 I am unable to detect any openings ; and the internal struc- 

 ture, at the fractures, .seems destitute of any organized 

 arrangement ; it is compact and granular-b'ke in appearance." 



It diff"ers from />'. digitata, it is .said, in the arms projecting 

 directly outward from the body and in not tapering : and in 

 the possession of tubercles. The locality is given as a branch 

 of Todd's Fork, near Wilmington, Ohio. 



I have not been able to see the specimen from which the 

 above description was made. It would .seem to be the same 

 as /?. digitata. Its occurrence in Ohio, if the locality be cor- 

 rectly given, and in beds of the upper portion of the Cincin- 

 nati group, is interesting, as it greatly extends the range of 

 the genus in time and in area. Dr. Beecher does not seem to 

 have been aware of this form, and nowhere makes any refer- 

 ence to it. 



Genus 12. — P.vtteksoni.a., S. A. Miller. 1SS2. 



" A solid, amorphous, calcareous sponge, uniform in struc- 

 ture, vesicular, and destitute of larger canals and openings. 

 .Spicules (?)." (Jour. Cin. vSoc. Nat. Hist., vol. 5, 18X4, p. 43.) 



Kcniarks. — The above is the original description given of the 

 genus. In 1889 Mr. Miller (North American Oeology and 

 PaUcontology, p. 163) enlarged it as follows: "Solid, amor- 

 phous ; no large openings ; lobed, pendent expansions on the 

 ui)])er surface, and bundles of fine filaments at the base, and 

 in the interif)r, which do not merge into the parenchyma of 

 the sponge ; .spicules unknown." It is probable that this genus 



