36 PROCEEDINGS OF THE NATIONAL MUSEUM. 



DICRANOPORA MEEKI (James). 

 Plate V, fig. 1. 

 Heloponi meeki James, Paleontologist, No. 1, 1878, p. 3. 



Ori(final desor qjt i > n.--' ' ViAy'AO'a.vy Qon>iis\:mg of very siimll cylin- 

 dricaror subcylindrical stems; sometimes branching dichotomously. 

 About 6 cells in the .space of a line measuring their longer axes, and - 

 arranged in rows between strong elevated longitudinal lines. The 

 cells are generally opposite each other in the rows, ))ut sometimes are 

 alternating; cell apertures long oval, margins not raised: length of 

 fragments observed from one-fourth to one-half an inch; diameter 



one-lifth of a line.'' 



The original and only description of this species, quoted above, is 

 good as far as it goes, but fails to state the two most important features, 

 namely, that the zoarium is bifoliate and is also jointed. Its zocecial 

 structure is that of the family Rlunidictyonid-^, and this fact together 

 with the jointed zoarium causes the reference of the species to the 

 o-enus Dicrmiopora. As in all species of this genus, the zoarium of 

 Z>. ineeU consists of either simple or dichotomously branched segments 

 with the lower end of each pointed for articulation and the upper end 

 or ends excavated to receive the pointed extremity of the following 



segments. . , 



D. meeki may be distinguished from all other species ot Dtcranopora 

 by its comparativelv long and extremely narrow segments, their aver- 

 ao-e length being 5.8 mm. and width about A mm. l^our rows ot 

 zooecia generally occupy each face of a segment, but sometimes only 

 three are found. 



()cci^rrence.-^ni& species was listed by James as from \V arren 

 County, Ohio, but his label states Cincinnati as the locality for the 

 type. ' Specimens occur often quite abundantly in the Mt. Hope mem-^ 

 ber in the vicinity of Cincinnati. 



ESCHAROPORA ACUMINATA (James). 



PtUodidya acuminata James, Catal. Foss. Cincinnati (Troup, 1875, p. 8. 

 EscharoporaacaminataVLmcn, (^eol. and Nat. Hist. Snrv., Mnuaesota, FmaT 



Rep., Ill, Pt. 1, 1893, p. 167. 

 Compare Ptilodidya falciformis Nicholson, Ann. Mag. ^at. Hist. (4), X\ , l»/o,| 



!>. 177, pi. -xiv, figs. 1-16. 

 The types of James Ptilodlctya ammlnata.^YoxQ to be of a sword-! 

 shaped Eseharopora from the Eden shales. To point out constant dif- 

 ferences between this form and Escharopora {Pt;iodictya)falc>forn,ts 

 from the Fairview formation is very difficult if not impossible and 

 James's name is adopted here as a convenient term for the Eden shale 

 form of this tvpe of E.rhampnra rather than as that of a good species. 

 James distinguished his species from Nicholson's by its narrower and 



A 



