R. Etheridge, jun.—Carboniferous Tubicolar Annelida. 367 
Through the researches of Mr. John Young, F.G.S., a form has 
been met with in the Carboniferous shales of Scotland possessing 
characters which appear sufficiently near to place them within generic 
affinity of Ortonia, Nich. 
Both Pacht and Eichwald have described forms which appear to 
me to be inseparable from Ortonia. The Serpula Devonica of the 
former’ is described as a small slightly bent tube, never becoming 
spiral, but tapering towards one extremity, and marked with indistinct 
growth-striz. It occurs at Kon-Kolodes on the Don, associated with 
Spirifer Anossofi. Serpula striatula, Kichwald,’ is a conical, curved, 
and attenuated tube, flattened on the attached side, convex on the free, 
but with the cavity of the tube circular. The free surface bears 
unequal, close, transverse striae, which are continued as lateral fringes 
on the object of attachment; it is of Devonian age, adhering to 
examples of Favosites polymorpha and Cyathophyllum flecuosum. We 
have in this latter species a point of much interest in the development 
of the growth-striz into a lateral fringe on each side, impinging on 
the object to which the tube is attached, and in this respect re- 
sembling Ortonia intermedia, Nich. 
18.—Ortonia carbonaria, Young. (Pl. VII. Figs. 87-40.) 
0. carbonaria, Young, Grou. Mac. 1873, Vol. X. p. 112. 
y A », Proc. Nat. Hist. Soc. Glasgow, 1876, ii. pt. 2, p. 223. 
* of Bigsby, Thes. Dey.-Carb. 1878, p. 243. 
Sp. char.—Tube small, conical, and straight, or slightly curved ; 
attached wholly by one side, or only a portion of it. Section circular. 
Surface ornamented by sharp, continuous, annulations or rings 
separated by interspaces of variable breadth, but usually a little wider 
than the ridges themselves, and crossed longitudinally by innumer- 
able fine microscopic striz. 
Obs.—This remarkable little organism is usually found loose with 
other minute fossils on washing the weathered shales from various 
localities, or is met with attached to the species of Producti, which 
appears to be its natural habitat. It possesses characters which 
render it of peculiar interest in connexion with the Silurian species 
described by Prof. Nicholson. In the first place, there is no cellular 
zone, as in the type species O. conica, thus showing a tendency 
towards O. minor and O. intermedia. Secondly, the annulations of 
the surface are crossed by very fine, in fact quite microscopic, longi- 
tudinal strie, a character not found, to my knowledge, in any of the 
Silurian species ; and lastly, I have in one or two specimens observed 
a tendency towards the imbricating nature of the segments described 
by Prof. Nicholson in O. intermedia. 
The measurements of this very Orthoceratite-looking little tube, 
given by Mr. Young, are—length 4 to } inch; diameter of the tube 
at the larger end =; to 345 of an inch; annulations, 35 in the space 
of + of an inch. 
Ortonia carbonaria differs from all the other species of the genus 
1 Beitrage zur Kenntniss d. Russ. Reiches, 1858, xxi. p. 107, t. 4, f. 5. 
2 Lethwa Rossica, i. p. 672; Atlas, f. 34, f. 4, a.-e. 
* 
