Page:TransRoySocCanada 16 4 159-167.djvu/9

 portions of these segments are defined from the axial portions in some segments by narrow, curved longitudinal grooves. They end in acute projections. The succeeding and last segment is formed of a fusion of somites. Anteriorly on this last segment there are two free epimeral projections. A small hemispherical tail-like area is marked by a median triangular depression suggesting articulation with a caudal spine which has been lost. In one specimen the entire posterior segment is lacking.