3866 8 =©R. Etheridge, jun. Carboniferous Tubicolar Annelida. 
17.—Vermilia? sp.ind. (Pl. VII. Fig. 35.) 
Sp. chars.—Tube tortuous, twisted, or curved, but never coiled upon 
itself in the form of a spiral; attached to the surface of submarine 
bodies, usually Crinoid stems and plates, by its whole length. Section 
subangular to round, but it is more usually seen in a compressed 
form; surface as a rule plain, or with indistinct transverse striations. 
Obs.—As before observed, Brown’s figure of V. minuta represents a 
small horn-like tube which cannot possibly include such a twisted or 
curved form as the present one, unless indeed the figure is wretchedly 
bad. The surmise of Messrs. Armstrong and Young is probably 
nearer the truth, that the Carboniferous form met with in Scotland 
is more allied to V. obscura, King, than to Brown’s species. 
Loc. and Horizon.—Skateraw Quarry, near Dunbar, in shale over 
the Skateraw Limestone; L. Carboniferous Limestone Group; and 
various other localities (Mr. J. Bennie). 
V.—Genus Ortonia, Nicholson, 1872. 
Ortonia, Nicholson, Grou. Mac. 1872, Vol. IX. p. 447. 
Brit. Assoc. Rept. for 1872 (pub. 1873), pt. 2, p. 119. 
Pal. Ontario, 1874, pt. 1, p. 122. 
Conchicolites, ’ Miller (pars), Cat. American Pal. Foss. 1877, p. 206. 
Gen. char.—Animal solitary, inhabiting a calcareous tube, which is 
attached along the whole of one side to some foreign body. ‘Tube 
slightly flexuous, conical, in section cylindrical, or somewhat flattened 
laterally, and subtriangular. Walls of the tube thick, and marked 
by annulations, which may, or may not extend completely round the 
tube (Nicholson). 
Obs.—The genus Ortonia was proposed by Prof. H. A. Nicholson 
to include small Tubicolar Annelides of the Silurian rocks, which are 
solitary, and adherent to foreign bodies along the whole of one side 
of the tube. The genus Conchicolites, Nicholson, includes essentially 
social tubes which are only attached by their bases to foreign bodies, 
grow up vertically side by side, and are often closely united laterally 
to one another. 
Ortonia is only accidentally social or aggregate, and is essentially 
a solitary form. Cornulites, on the other hand, includes tubes which 
are always free, at any rate when grown up. The original diagnosis 
of Ortonia described the genus as possessing a peculiar cellular zone 
down the unattached side of the tube; but as this is confined to the 
type species, O. conica, and as two other Silurian species have since 
been described, O. minor and O. intermedia, in which this zone is not 
met with, Prof. Nicholson now abandons this character as of generic 
importance. Judging from the structure of O. intermedia, the tube 
would appear to be made up of a succession of imbricating conical 
segments, the upper edges of which produce the encircling ridges or 
annulations. 
Mr, A. 8. Miller has, in his “‘ American Paleozoic Fossils,” placed 
Ortonia as a synonym for Conchicolites; but as Prof. Nicholson still 
maintains their generic distinction, I prefer following his opinion, 
especially as, so far as I know, no reasons have been assigned for the 
above union. 
2? ? 
