138 VERMES phylüm iii 



Terehella Cuv. (Fig. 218, I). Cylindrical, elongate, more or less beut 



Fi(!. 218. 



A, Serpula Umax Goldf. Middle Jura ; Franconia. ß, C, S. gurdialis Schloth. Upper Cretaceous : Banne- 

 witz, near Dresden. D, S. convoluta, Goldf. Middle Jura; Stuifen, Wurtembercr. E, S. socialis Goldf. Middle 

 Jura ; Lahr, Baden. F, Same, enlarged. G, S. septevisulmta Reich. Upper Cretaceous ; Bannewitz. H, S. 

 (Rot.ulariaJ)efr.)spirulaeaIjam. Eocene ; Monte Berici, near Vicenza. I, TerpheUalapilloides Münster. Upper 

 Jura ; Streitberjr, Franconia. 



tubes, composed of cemented grains of sand, fish-debris, or other adventitious 



particles. Lias to Eecent. 



Spirorbis Daudin {Microconchus Murch.) 

 (Fig. 219). Minute, snail-like or spirally 

 enrolled calcareous tubes, cemented by the 

 flattened under side. The spiral may be 

 either dextral or sinistral, and is usually 

 ornamented externally with concentric Striae 

 or annulations, sometimes with tubercles or 

 spines. Abundant in the Paleozoic forma- 

 tions from the Ordovician onward, and also 

 at the present day ; somewhat less common 

 in the Mesozoic and Cenozoic eras. Kecent 

 species usually adherent on seaweeds. 



Fig. 219. 

 Spirorhis omphalodes (Goldfuss). 



Tubes 



seated upon a Brachiopod shell {Schiichertella 

 umhraculnm). Devonian ; Gerolstein, Eifel. 



The foUowing genera are 

 regarded as Annelids, but their systematic position is doubtful : 



commonly 



