10 BRITISH PALAZOZOIC FOSSILS. [ Zoopuyra. 
Genus. PROTOVIRGULARIA (J/°Coy). 
Etym. zparos, primus et Virgularia. 
Ref.—M°Coy, Annals of Nat. Hist. 2nd Series, Vol. VI. p. 272. 
Gen. Char.—Stem capillary, dichotomously branching, closely set on each side with short, alternately 
placed pinnules, either contracted close up to the axis in a doubly oblique alternating series, or extended 
with a gentle upward and outward curve, each pinnule transversely ridged, with about five parallel cylin- 
drical cells placed at right angles to its length. 
This is a most interesting type, as it perfectly resembles the recent Virgularia mirabilis in the 
form of its axis and the structure of the transversely ridged celluliferous pinnze, both in the curved 
extended, and in the straight contracted states; while by its branching it approximates to the Hydroida ; 
thus completing the passage between that great group and the eight-rayed corals, by the present genus on 
the one hand, and the free Hydroid Graptolites on the other. I know but one species which resembles at 
first sight the Graptolites ramosus of Hall; but that species has only simple denticles on one side of the 
branches, while this differs from it and all other Graptolites by its two alternating rows of moveable 
pinnules, transversely furrowed, apparently to contain each a number of polypes, as in the recent group to 
which I have approximated it. I have little doubt the so-called Graptolites amplewicaule, figured by Hall 
(Pal. N. York, t. 26. f. 11), may ultimately be referred to the same group, though the characteristic cell- 
furrows at right angles to the upper edge of the pinnules have not yet been noticed in it. 
PROTOVIRGULARIA DICHOTOMA (J/‘Coy). Pl. 1. B. figs. 11 and 12. 
Ref —M ‘Coy, Annals of Nat. Hist. 2nd Series, Vol. VI. p. 272. 
One specimen, about two and a half inches long, branches twice at an angle of about 30°, and shews 
all the pinnules extended at right angles to the capillary axis with a gentle upward curvature, like the living 
Virgularia in the same state; another simple fragment about the same length has them half-expanded, 
being nearly straight and oblique to the axis; a third fragment has them quite contracted, resembling a bit 
of narrow braid, exactly like the contracted state of the recent Virgularia mirabilis. This one shews very 
plainly the transverse cell-ridging. Width rather less than one line; four pinnz in the space of two lines. 
Position and Locality—In the slate at Lockerby, Dumfriesshire. 
Explanation of Figures.—Plate 1, B. fig. 11. Branched specimen, natural size, from Lockerby, shewing 
the pinnules extended.—Fig. 11 @. Portion of ditto, magnified six diameters, shewing each of the pinnules 
divided by tubular sulci for the polyps.—Fig. 12. Do. Fragment with the pinnules contracted up against 
the stem.—Fig. 12a. Do. Magnified six diameters, shewing the tubular cellules on the margin of each 
pinnule in its contracted state. 
PyRITONEMA FascicuLus (M°Coy). Pl. 1. B. fig. 13. 
Ref—M°Coy, Annals of Nat. Hist. 2nd Series, Vol. VI. p. 273. 
I have proposed the above name for a singular fragment of a fossil from the dark limestone of Tre Gil, S. 
of Llandeilo. It is nearly straight, about two and a half inches long, four lines wide, and one and a half lines 
thick, and marked longitudinally with coarse thread-like ridges, about the third of a line in diameter, occa- 
sionally cut by small sharp transverse wrinkles; the whole having some resemblance to an Jchthyodorulite 
(Onchus or Ctenacanthus). On first seeing the specimen I doubted this reference, from observing that the ridges, 
instead of being merely superficial, thicker, and more numerous at one end as they should be on this view, 
seemed equally thick at each end, and clearly not in one plane, but those at the surface of one part plunging 
into the mass and giving place to others emerging from it. Owing to the skill and kindness of Mr. Anthony, 
of Caius College, two sections for the microscope were prepared, which proved that the whole mass was really 
