56 PROCEEDINGS OF THE NATIONAL MUSEUM. voi,. xxx. 



one-tenth of a line in diameter. Cells iinisorial, each growing by a 

 pointed base from the cell below, and expanding gradually to the 

 mouth; two or three cells in the space of a line. Apertures terminal, 

 elevated, and nearly or quite the diameter of the cells and placed on 

 their front face.'" 



Mr. James's description l)rings out all the essential features of this 

 variable species. Its constant chara(;ter,s are the elongate, club-shaped 

 zo(jecia increasing very gradually and regularh" in width from the 

 narrow proximal portion to the wider rounded anterior end, where a 

 diameter of about .12 mm. is reached. Considerable variation occurs 

 in the length of zocjecia of the same zoarium, so that speciric differences 

 made upon this character can not be maintained. At certain horizons, 

 and especially in the Coi'ryville bed, very luxuriant growths of this 

 form are found upon other organisms, and it is in such specimens that 

 the greatest variation is exhibited. Mr. Miller applied the name S. 

 prouta7ia to the very, elongate form from the Corr3^ville bed at Cincin- 

 nati, while specimens with the same characters, but coming from the 

 lower part of the Eden shale were described as S. tenulssima by Mr. 

 Ulrich. The form with short zotecia was named Rliopalonaria pev- 

 teiruls ])y Mr. Uli'ich, ])ut later placed by him as a s^nonAan of S. -prou- 

 tana Miller. Nickles and the writer recognized Mr. James's name, but 

 considered S. tenuhmaa of sufficient value to rank as a variety. Fur- 

 ther study may indicate that this latter form might still be ranked as 

 a variety instead of being considered a s^nionym as above. 



Occurrence.— y^v . James's type lot contains specimens from various 

 horizons of the Covington and Richmond groups in southwestern 

 Ohio. The species I'anges through the various divisions of the 

 Mohawkian and Cincinnatian divisions of tlie ()rdo\ician, and has also 

 a wide geogi-aphical distribution. 



STROMATOPORA ? LICHENOIDES James. 



Slrnmatopora / lii-heiioiilex J .\mk><, Pali'(»ntoloii;ist, No. 3, 1879, p. 18. 

 StroiiiatdjMini f Hi-hnwidrs J. F. Jamkh, .lour. Cindnnati Sof. Nat. Hist., XV, 

 1892, p. 90. 



Althougii not described as bryozoa, the types of this species prove 

 to belong to this class. All of the specimens are basal expansions of 

 the articulated l)ry()zoan Artliropoi'a. Five of the examples are from 

 the Richmond group and are undou])tedly the bases of a form of 

 Arthropoi'n n/itiffirt found \ery abundantly in these rocks; the remain- 

 ing four specimens aie from the Eden shales at Cincinnati and prob- 

 ably belong to Art/iroj>ora cleavelandl James, Several species of 

 Artliroporn occur in the Eden, but as A. cleavelandl is the most 

 abundant, it is most probable tiiat the P2den specimens are of this 

 species. 



