R. Etheridge, jun.—Carboniferous Tubicolar Annelida. 305 
circumference (the convex and concave faces of the curve), stronger 
than the rest of the shell, and prolonged at the posterior end (M‘Coy). 
Obs.—In neither of the papers in which Mr. Macleay proposed the 
name Serpulites was the genus defined, and, so far as I am aware, one 
of the few definitions which have appeared is that by Prof. M‘Coy. 
The Chevalier d’Hichwald used the term Campylites (non Campu- 
lites, Deshayes) for such worm-tubes, and ascribed the name to one 
of the Sowerbys, but I have been quite unable to find a trace of 
such a genus in any of their writings. It is not given in either 
Agassiz’s “ Nomenclator,” Bronn’s “Index,” Morris’s “ Catalogue,” 
Pictet’s ‘‘ Paléontologie,” Geinitz’s ‘“ Grundriss,” Marschall’s “ No- 
menclator,” Miller’s Catalogue,” or any work of the kind I have 
been able to consult. Under any circumstances, unless prior to the 
proposal of Serpulites in the “Silurian System,” the name Campylites 
will not stand as a substitute for Serpulites, for, although the latter 
was not defined for some years after its first enunciation, its stability 
is insured by the description and figuring of the type species, 
S. longissimus (Macleay, in Murchison’s Sil. Syst. 1839, p. 700). 
Prof. M‘Coy has shown that, in at least two British species of 
Serpulites, opposite points of the circumference of the tube were 
thickened, forming two longitudinal ridges, not due to pressure. A 
similar structure has been shown to exist in a Canadian Silurian 
species by the late Mr. Billings, viz. S. dissolutus, Bill.,) in which 
there is an elevated wire-like margin running the whole length of 
the tube. Serpulites dispar, Salter, and S. longissimus, Murch., also 
possess this raised border. Numerous species of Serpulites have been 
described by authors in which these thickened edges of the tubes 
have not been observed. It becomes a question, therefore, whether, 
seeing the occurrence of this character amongst so many species, it 
will not be necessary to look upon it as of generic value, and, in 
consequence, eliminate from Serpulites all those tubes in which it has 
not been observed. 
The term Serpulites, before being employed by Macleay, was 
made use of by both Blumenbach and Schlotheim in a generic sense. 
The former described Serpulites coacervatus in his “ Specimen 
Archeologiz telluris terrarumque imprimis Hannoveranarum” as 
early as 1803,? whilst the latter named several species in 1820,° but 
as those of both authors have since been referred to Serpula, the name 
Serpulites remains open to be employed in the sense proposed by 
Macleay. 
The following list comprises those Serpulites possessing bordered- 
tubes, or otherwise, with which I am acquainted :— 
1. SrmurtrAn. 
a. With borders. b, Without borders. 
Serpulites dispar, Salter. Serpulites Murehisoni, Hall. 
Ap longissimus, Murch. va curtus, Salter. 
c dissolutus, Billings. < perversus, M‘Coy. 
” Jistula, Hall. 
1 Canad. Pal. Foss. i. p. 56. 
BO 2a, Ua ey, Te Oe 3 Die Petrefactenkunde, etc., p. 96. 
DECADE II.—VOL, VII.—NO. VII. 20 
