322 BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Genotype. Pachytheca (Pori.no) filiformis D'Orbigny, 1852. 

 Range. Campanian-Midwayan. 



PACHYTHECA STIPATA, new species. 



Plate 6, figs. 13-15. 



Description. The zoarium is free, cylindrical or escharian, bifurcated. The 

 zooecia are little distinct, elongated ; the frontal is somewhat convex, smooth. The 

 ascopore is large, deeply imbedded, placed at the middle of the zooecia 011 the 

 median line. The peristome is salient, wide, supporting four small avicularia; 

 the peristomice is orbicular. 



. rZz=0.45-0.50mm. \hpe=Q.lQmm. 



Measurements. Zooecia^ 7 _ , . l eristoimce \ , 



((2=0.30 (?) mm. (tpe=Q.Wrcim. 



Affinities. The peristomes are crowded qnite close to one another as in 

 Beisselina. The species differs from Pachytheca (Eschara) defrancei Hagenow, 

 1851, in the presence of avicularia on the peristome. 



It differs from Pachytheca (Porina) filiformis D'Orbigny, 1852, in its rarely 

 cylindrical zoarium and in the presence of many (and not of one alone) .peristomial 

 avicularia. 



Occurrence. Midwayan (Clayton limestone) : Luverne, Crenshaw County, 

 Alabama (common). 



Cotypes.Cnt. No. 63819, TJ.S.N.M. 



Gtnus BEISSELINA Canu, 1913. 



1933. Beisselina CANU, Contributions a 1'etucle des Bryozoaires fossiles, 13, Bryozoaires 

 jurassiques, Bulletin Societe Geolofeique, France, ser. 4, vol. 13, p. 138. 



The tubules are large and often are replaced by some small avicularia; they 

 hide the true zooecial form. The zoarium is free and escharian. 



Genotype. Beisselina (Eschara) striata Goldfuss, 1820. 



Range. Cenomanian-Jacksonian. 



It is impossible to confuse the genera Acropora Reuss. 1869, and Beisselina 

 Canu, 1913. However, it is difficult to find any physiologic character clearly 

 different. It is true that we are always ignorant of the function of the avicularia 

 and of the tubular tremopores. 



BEISSELINA FORATA, new species. 



Plate 6, figs. 16-20. 



Description. The zoarium is free, escharian; the two lamellae, back to back 

 are inseparable. The zooecia are indistinct. The peristome is thin, sharp, very 

 little salient; the peristomice is orbicular. The frontal pores are large, orbicular. 

 numbering 5 or 6. The ascopore is large and in aspect little different from the 



other pores. 



. 

 Measurements. Peristomice 



thpe=O.Q9mm. 



t , 

 \tpe=0.09mm. 



