vine: carboniferous and PERMIAN POLYZOA. 
75 
1836. Fliistra? parallela, Phillips. Geol. of Yorkshire, p. 200, pl.i., 
figs. 47, 48. 
1844. Vincularia parallela, M'Coy. Carb. Foss. Ireland. 
1854. Sulcoretopora parallela, D'Orb. Morris's Cat. Brit. Foss. 
1880. Ptilodictya (?) parallela, Vine. ( = Stictopora ? Hall). First 
Rep. Brit. Assoc. Carb. Polyzoa 
1883. Arcanopora parallela. Vine. Fourth Brit. Assoc. Rep. Foss. 
Polyzoa. 
1884. Cystodictya parallela. Vine. Naturalist, Yorkshire, p. 65. 
1884. ,, Vine. Proc. Yorkshire Geol. Soc, vol. ix., p. 26. 
1884. „ Ulrich. Jour. Cincin.Soc Xat. Hist., pp. 36-38, vol. vii. 
1887-8. „ Young. Jour. Edinb. Geol. Soc, p. 402, vol. v, pt. iii. 
Specific characters. Zoariiim calcareous, composed of thin 
flattened sub-parallel branches, having two layers of cells, but with- 
out dividing laminae. Branches linear, occasionally dichotomous, 
bearing from three to seven rows of round or oval vestibular openings 
in furrows ; each row separated by apparently solid bars, excepting 
those near to the edges of the fronds or branches ; margins non- 
poriferous and striated. Zoceciw semitubular, or slightly pyriform in 
section, but rarely exposed superficially ; orifices of Zooecia concealed ; 
vestibular openings oval or round, frequently with a granulated 
peristome, lower edge of peristome occasionally crescentic and pro- 
duced ; dividing ridges or bars also granulated ; three of these 
openings occupy the space of about l-20th of an inch in length. 
Gonocyst, an inflation of the surface, or margins of the Zoarium. 
Operculw (J) 
Distribution. Yorkshire : Type sp., Phillips, Whitwell, Hurst 
and Richmond. Derbyshire : Castleton. North Wales : Halken, 
(rare). Lancashire : Holker Park, Gleaston. Northumberland : 
Redesdale, Fourstones. Scotland : Several localities. America : 
Sub-Carb. Rocks. (Ulrich;. 
This peculiar Carboniferous Polyzoon appears to me to be a sur- 
vival of the Stictoporidaj group so prevalent, as individuals at least, 
in the early Silurian rocks of America. Further on I shall give 
ample illustrations of the minute external and internal structural 
features of this and allied forms. 
