Sub-Kingdom IV. VERMES. Worms.’ 
Bilaterally symmetrical animals with unsegmented or uniformly segmented, and 
usually elongated, bodies. Segmented lateral appendages wanting. A dermal 
muscular system and paired excretory canals (water-vascular system) present. 
Of all the larger divisions of the animal kingdom, none is so poorly 
adapted for preservation in the fossil state as the Worms, whose bodies, as a 
rule, are totally without hard parts. 
All Worms are laterally symmetrical, and in every case a dorsal and 
ventral surface is distinguishable. The group of unsegmented Worms (Vermes 
proper, as restricted by some authors) have either flat or cylindrical bodies, 
and are accordingly distinguished as Platyhelminthes or Flat Worms, and Nema- 
thelminthes or Round Worms. But with the exception of a few rare parasitic 
forms discovered in Carboniferous insects, or in insects enclosed in amber, 
neither of these classes is represented in the fossil state. 
The segmented Worms, or Annelida, are characterised by a division of the 
body into metameres, which, although primitively alike, do not always remain 
homonomous. They have a brain, a circumoesophageal ring, a ventral chain of 
ganglia, and a vascular system. The body is more or less elongated, and 
sometimes flattened, sometimes cylindrical. According as the internal 
segments correspond exactly with the external, or as each internal segment 
corresponds to a definite number (3, 4, or-5) of the external rings, two 
1 Literature : 
Pander, C. H., Monographie der fossilen Fische des silurischen Systems des russisch-baltischen 
Gouvernements, 1851. 
Ehlers, E., Die Borstenwiirmer (Annelida Chaetopoda). Leipzic, 1864-68. 
Ehlers, E., Ueber fossile Wiirmer aus dem lithographischen Schiefer in Bayern (Palaeontographica, 
Bd. XVII.), 1868. 
Claparéde, E., Recherches sur la structure des Annélides sédentaires, 1873. 
Newberry, J. S., Palaeontology of Ohio, vol. Il. part 2, 1875. 
Hinde, G. J., On Conodonts from the Chazy and Cincinnati Groups ; and on Annelid Jaws from the 
Cambro-Silurian, Silurian, and Devonian Formations in Canada, and from the Lower Carbon- 
iferous in Scotland (Quar. Journ. Geol. Soc., vol. XXXY.), 1879. 
Hinde, G. J., On Annelid Jaws from the Wenlock and Ludlow Formations of the West of England 
(Quar. Journ. Geol. Soc., vol. XXXVI.), 1880. 
Etheridge, R., jun., British Carboniferous Tubicolar Annelides (Geol. Mag.), 1880. 
Nathorst, A. G., On the Tracks of some Invertebrate Animals and their Palaeontological Significance 
(K. Svensk. Vetensk. Akad. Handl., Bd. XVIII., XXI.), 1881-86. 
Hinde, G. J., On Annelid Remains from the Silurian Strata of the Isle of Gotland (Bihang till K. 
Svensk. Vetensk. Akad. Handl., Bd. VII.), 1882. 
Zittel, K. A., and Rohon, J. V., Ueber Conodonten (Sitzungsber. Bay. Akad. Wissensch., Bd. XVI.), 
Clarke, J. M. Annelid Teeth from the Lower Portion of the Hamilton Group, New York (Sixth 
Annual Report State Geologist, 1886). 
