164 



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GKxns RHOMllOPORA. Meek. 



[Syn. : Orthopora. Hall. Ety. : Wtomhu><, ilionih ; porox, pore.] 

 (1872: Meels Pal. Eastern Nebraska, p. 141.) 

 Bryozoum consistiiiii' of solid ))i'anehe8, with cylindrical 

 cells, which pass outward troiii an iina<iinarvaxis; cell.swith 

 transver.se plates or tabulae; apertures separated bjM-idges, 

 which are often broad, and either continuous or unite to form 

 rhombic or polygonal cell spaces. Ridges bearing short 

 spines or nodes, and containing tubuli near the surface, from 

 the gr()\A'th of the nodes. 



Rhombopok.\ (?) TKAxsvERSA. (Hall.) (Fig. 52.) (Pal. 

 N. Y., Vol. VI., p. 187, Pis. LV., LVI.) (Simpson uses this 

 species to illustrate the genus. See Hand-book Pal. Bryo- 

 zoa, PL XIX.) 



Distini>uisInnLi,- Characters. — Diameter of branches about 



, 1.7-") mm. : oval cell ai)ertures in loniiitn- 



'i^o*-i'ii'^r-"l'i^ 'lii^''l I'ows, diagonal i-ows, or irregularly 

 k^-'0:'^--J:Mi dis]»()sed: flat or sli!>-htlv concave inter- 

 -"^(■rr--'^-''''* apertural space, with small, prominent 

 <mns™.^'T^fmsment Hodcs oi" granules surrouudiug the aper-- 



natural size, ami a purtion , • , ^ . , 



of a branch eniaiKv'i. .x iv tiii'es ; penstomfe prominent. 



(after Hall anil Siinjisiin). ^-, , . , ^-^ ., 



lound in the Hamilton grou]), at 

 West Hamburg, Erie County, X. Y.' (Hall.) 



Rhombopoka polygoxa. (Hall.) (Not figured. ) (Pal. 

 N. Y., Vol. VI., p. 176.) 



Distinguishing Cliaravters. — Infrecjuent b i f u r cations; 

 wideh" diverging branches with diameter of 1.25 to 1.50 

 mm. : oval cell apertures, alternating in adjacent rows, so as 

 to make diagonal series at forty-five degrees to the axis; 

 angular or rounded, granulose interspaces, with conical 

 nodes at the angles. 



Found in the '"Hamilton group. West Hamburg, Erie 

 County, X. Y."" (Hall); also four to five feet below the 

 Encrinal limestone, at Section 6, Eighteen Mile Creek 

 (rare). 



Rho.mbopoka hexagoxa. (Hall.) ( Fig. 53.) ( Pal. X. X., 

 Vol. VI., p. 178, Pis. LV., LVI. Simpson, PL XIX., Fig. 12.) 



