322 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Genotype. — Pachytheca (Porina) 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 on the 
median line. The peristome is salient, wide, supporting four small avicularia; 
the peristomice is orbicular. 
M easurements . — Zooecia 
(Ls= 0.45-0.50 mm. 
i?s=0.30 (?) mm. 
Peristomice 
hpe= 0.10 mm. 
A»e=:0.10mm. 
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 P achy theca ( 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). 
Gotypes. — Cat. No. 63819, TJ.S.N.M. 
Genus BEISSELINA Canu, 1913. 
1913. Beisselina Canu, Contributions a l’etude des Bryozoaires fossiles, 13, Bryozoaires 
jurassiques, Bulletin Societe Geologique, 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, 1826. 
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. 
<hpe—0.0S) mm. 
a 
Measurements . — Peristomice 
\lpe= 0.09 mm. 
