BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



sider this species as an easily recognized, characteristic fossil. Unfortunately, the 

 species has not yet been discovered in many of the localities of the Midwayan. 



Oit-in-riiK-,'. Midwayan (Clayton limestone): Owl Creek. :.'] miles northeast 

 of Ripley. Mississippi (common); Mabelvale, near Little' Rock. Arkansas (very 

 rare). 



i '////>,. Cat. No. 63789, U.S.X.M. 



CONOPEUM WILCOXIANICUM. new species. 



Plate 9, figs. 1-7. 



Description. The zoarium is iricrnsting, of one or more lamellae, or free and 

 bilaminate. The zooecia are distinctly elongated, elliptical, or pyriform: the mural 

 rim is flat, finely granulated, proximally widened. The opesium is anterior, ellip- 

 tical or pyriform, entire or denticulated. The interopesial cavities are distinct, 

 lozenge shaped. There are two distal impressions. 



. f Ao=0.26-0.30 mm. . fZ3=0.40-0.44 mm. 



Measurements. Opesia , /ooecia 7 



(lo=0.'20mm. |fe=0.36 mm. 



Affinities. This species differs from Oonopeum hoockeri in the absence of the 

 irymnoeyst, from C. concavitm in its much larger interopesial cavities and from 

 C. lacroixii in the width of its mural rim. It is rarely incrnsting. while the three 

 species mentioned are always so. Its zooecial length is likewise a little greater, and, 

 furthermore, it does not corrode the substratum, as in C. hooclicri and C. concavum. 

 Total regeneration occurs rather frequently and manifests itself by a collar border- 

 ing the opesia. 



Occurrence. Wilcoxian (Bashi formation) : Woods Bluff, Alabama (common). 



< h/i>, *. Cat. No. 63831, U.S.X.M. 



CONOPEUM (?) SIMILIOR, new species. 



Plate 9, figs. 8, 9. 



Desmption. The zoarium incrusts shells. The /ooecia are distinct, elongated, 

 elliptical, separated by a deep furrow: the mural rim is regular, finely granulated. 

 almost flat, a little larger in its proximal portion. The opesium is elliptical, finely 

 crenulated. The calcified zooecia have a linear orifice and a semilunar distal furrow. 



(0=0.30 mm. . \Ls-OAOmm. 



Measurements.-Opesmm _ 8 mm . ' cia lfe=0.30 mm. 



Affinities. This species resembles Conopeuni lacroixii exactly in its zooecial 

 form and in its ralrilieil /ooecia. but it differs in it> smaller micrometric dimensions. 



The two specimens found do not bear interopesial cavities, and hence our doubt 

 as to the generic reference. The species requires further examination. 



Occurrt nc, . Wilcoxian Bashi formation) : Woods BlutV. Alabama (rare). 



Cotypes.C&t. No. C,:',N:W. U.S.N.M. 



