Report of the State Geologist. 213 



Lamellosa (a septum in ventral valve).* 

 S. sulcata, Hisinger. Niagara. 

 S. perlamellosa, Hall. Lower Held. 

 S. raricosta, Conrad. Corniferous. 

 S. sculptilis, Hall. Hamilton. 



S. ziczac, Hall. Hamilton ={S. consobrina, D'Orb.) 

 S. mesacostalis, Hall. Chemung. 

 S. solidirostris, White. Kinderhook. 



Shell Punctate. 



A species undetermined from the Up. Waverly and Keokuk. 



S. transversa, McChesney. Chester. 



S. spinosa, Nor. & Prat. Chester. 



S. Kentuckensis, Shumard. Up. Coal Measures. 



Lamellosa (no septum in ventral valve). 

 ? S. Engelmanni, Meek & Worthen. Lower Helderberg. 

 S. Cumberlandia, Hall. Oriskany. 

 S. Bubmucronata, Hall. Oriskany. 

 S. mucronata, Conrad. Hamilton. 

 S. macra. Hall. Corniferous. 

 S. bimesialis. Hall. Hamilton. 

 S. subattenuata, Hall. Hamilton. 

 S. varicosa, Conrad. Hamilton. 

 S. segmenta. Hall. Hamilton. 



Mesio-plicata (non-punctate). 

 S. arenosa, Conrad. Oriskany. 

 S. divaricata, Hall. Corniferous and Hamilton. 

 S. Grieri, Hall. Corniferous. 

 S. Orestes, Hall. Upper Devonian. 

 S. Whitneyi, Hall. Upper Devonian. 

 S. Hungerfordi, Hall. Upper Devonian. 

 S. disjuncta, Sowerby. Chemung. 

 S. Marionensis, Shumard. Choteau. 

 S. Missouriensis, Swallow. Choteau. 

 S. Vernonensis, Swallow. Kinderhook. 

 S. biplicata, Hall. Kinderhook. 



* The presence of a septum in the ventral valve has been regarded as evidence of the 

 relationship of these forms to Spirifeeina, and some of the species have been cited 

 under that genus. The author, long ago, recognized this feature as allying these 

 lamellose forms with the genus Spirifei'ina, but thus far we have failed to find the 

 punctate shell struotare characteristic of that genusi 



