76 
vine: carboniferous and permian polyzoa. 
Cystodictya parallela is met with in small fragments both in 
Yorkshire and Derbyshire, and sti]l more minute fragments in Wales. 
In Lancashire and Northumberland the examples of the species vary 
very much, and I have fragments with from three to seven rows of 
zocecia in the branch, but I do not see any material difference so far 
as facial or structural characters are concerned in any of the British 
examples of the species, except in a few fragments found in North 
Lancashire. In some of these examples there are wavy instead of 
straight bars, (Fig. 19, p. ii), but whether they should be placed as a 
variety of C. parallela, or otherwise my material is not abundant 
enough to decide. In Scotland C. imrallela ''occurs in both the 
eastern and western districts in the limestone strata of our coal-fields, 
but chiefly in the Lower Limestone shales. At Auchenskeock quarry, 
near Dairy, Ayrshire, it is sometimes met with in linear fronds varying 
from two to three inches in length."* Mr. Young makes no mention 
of the mode (if any) of branching of the "linear fronds," and 
Phillips (Geol. Yorks. p. 200) says : — " No sign of ramification." 
Cystodictya raricosta, M'Coy. 
1844. Vincularia raricosta, M'Coy. Carb. Foss. Ireland, p. 198, 
pi. xxvii., f. 11. 
1854. Sulcoretepora raricosta, M'Coy. Morris's Cat. Brit. Foss. 
Specific characters. Elongate, parallel sides, section elliptical 
most convex on the porous side ; poriferous face convex, marked with 
fine sharp parallel keels, enclosing between them four rows of pores. 
Pores round, or slightly oval, with permanent margins placed twice 
their diameter apart, but irregularly with regard to each other. 
Reverse flattened, faintly marked with exceedingly fine, numerous, 
waving striae, sides indented each hj a prominent row of pores. . . . 
The species is distinguished from Cystodictya (Flustra) parallela 
Phillips, by having pores in the lateral furrows. 
The above is M' Coy's description, and it very fairly indicates 
the superficial characters of this peculiar form, judging from the 
Scotch examples supplied to me by Mr. Young, but English examples 
are rare. In the Yorkshire shales only a few poor compressed frag- 
ments have, as yet, been found. In the Lancashire shales, small, 
♦ Jchn Young, (Bibliog.), 18«7, see ante. 
