89 



This si)eeics is (juitc distinct from all othci-s in almost every 

 respect and may not belonif to Cyrtoceras. When compared 

 with C (lildldtiun, it will be noticed that the surface is furrow- 

 ed instead of imbricated and the sejita are not half as numer- 

 ous. It is not necessary to draw comparisons witli other species. 



Found hi the Upper Coal Measures, at Kansas City. Mis- 

 souri, and now in the collection of Wm. F. E. Gurley. 



SUBKINGDOM AKTICULATA. 



CLASS ANNELIDA. 



ORDER TUBICOLA. 



Family SERPULID^. 



spikorbis b[-aiki, u. s]i. 



Pphife I ', Fig. I'l. a coil (illaJclift lo Pliili/>ttoiii<i, hrondlieadi : 



Ficj. 11. (Ill olii Sjiirimi'ii with ilir inili'iior cml 



proluriiji^d nptvaril. 



Shell sinistral and in its yoiin.ir state attached throuii'hout 

 its lenii'th. Umhiliriis wide. Surface mai'kcd with unequally 

 distant rings of growth. In an old specimen, as shown by 

 Figure 14. the anterior end is pi-olonged and stands ujjright. 

 The lower side of the shell, that attached to some foi-eign ob- 

 ject is flattened, otherwise a ti'ansAei'se section is cii'cular. The 

 aperture seems, in all stages of gi'owth, to have been directed 

 upward and when a complete coil, foi- attachment, had been, 

 formed tlie further growth was in tlie forui of a loose spiral 

 or upright tube. 



Five specimens belonging to this species have been examined 

 and the growth of the spiral in all cases, was to the left as 

 sinistral. About (me coil and a quarter or less than <mo turn 

 and a half attached to the foreign substance. The transverse 

 ridges are closer and tiner on some specimens than upon others, 

 but always more or less irregular, and sometimes quite coarse 

 and wavy, indicating lines of growth, i-atliei- thau surfac-e or- 

 namentation. 



This syjccies is distinguish(>d by its sinistral growth. rreed(_)m 

 towards the aparture. and surfaci^ lint's of growth. 



Pound in the Chouteau limestone, at Sedalia, Missouri, and 

 now in the collection of S. A. Millei-. The specific name is in 

 houor of R. A. Blair, the original collector. 

 —12 



