scHUCHEKT] CLASSIFICATION OF PROTREMATA. 133 



2*'. Subfamily Orthothetin^ Waageii, 1884. 



Stropbomeuiiiii' (partim) W.aagen, 1884. 



Stropbomenoids witb tbe vertral valvo convex during early growtb, 

 becoming- subse(|uently concave. 



? Ortbidium Hall and Clarke, 1892. Streptorbyucbus King, 1850. 



Stropbomeua Blainville, 1825. Derbya Waageii, 1884. 



Hemipionites Meek, 1872 (not Pan- Kayserella Hall and Clarke, 1892. 



^^"' 1^30). Meekella Wbite and St. Jobn, 1870. 



Ortbotbetes Fiscber de Waldbeim, Triplecia Hall, 1859. 

 1007 ' ' 



^°^*- Dioraniscns Meek, 1872. . 



OrthisKiug, 1850 (not Dalinau, 1828). ^ Mimulus BaiTande, 1879. 

 Hipparionyx Vanuxem, 1842. stvej^fi^ Davidson, 1881. 



3. Family THECTDIID.E Gray, 1840. 



Cemented Stropbomenacea in wbicb tbe interior of the sbell is 

 impressed witb variously indented bracbial furrows. 



3^ Subfamily Lyttoniin.^: Waagen, 1883. 

 ThecidiidiB witb tbe bracbial markings common to botb valves. 



Lyttonia Waagen, 1883. j Oldbamina Waagen, 1883. 



Leptodus Kayser, 1882. I 



3''. Subfamily Thecidiin^ Dall, 1870. 

 Tliecidiidse witb tbe bracbial markings restricted to tbe dorsal valve. 



Tbecidia Defrance, 1822. ! Eudesella M. Cbalmas, 1880. 



Thecidiiun Sowerby, 1824. j Pterophloios Gilmbel, 1861. 



Lacazella M.-Cbalmas, 1880. 

 Tbecidiopsis M.-Cbalmas, 1887, 

 Tbecidella M.-Cbalmas, 1887. 



Ractryninm Emmerich, 1855. 



(In error. Not Bactrilliuni Herr. ) 



Davidsonella M. Cbalmas, 1880. 



2a\ Family PRODFCTID.E Gray, 1840. 



Prodnctina Giebel, 1846. 

 Stropbomenacea witb bollow ancboring spines. 



2a^\ Subfamily OHONETiNyE Waagen, 1884. 



Cbonetida? Bronu, 1862; Hall and Clarke, 1895. 



Productida' witb tbe ancboring si)iiies restricted to tbe ventral 

 cardinal margin. 



Cbonetes Fiscber de Waldlieim, Cbonostropbia Hall an<l Clarke, 

 1837. 1892. 



Leptajna McCoy, 1844 (not Dalmau, Cbonetina Krotow, 1888. 



1828). 



Anoplia Hall and Clarke, 1892. 

 Cbouetella Waagen, 1884. 



Cbouetella Krotow, 1884 (not 

 Waagen, 1884). 



