Claxslp' cation of t lie lircK'hiopodo. — SchiicJiert. 153 
Orthothetes, Fischer de Waldli. ? ?Badiotella. Bittner 1S90. 
1837. 
Orthis, King 1850 (not Dal- i Triplecia, Hall 1859. 
man 1828). ' Dicraniscus, Meek 1872. 
Hipparionyx, Yanuxem 1813. Mimulus, Barrande 1879. 
Streptorhynchus. King 1850. Streptis. Davidson 1881. 
Subfamil}^ RafinesqI'IN.!-;,* n. subfam. 
Lepttenacea, Braun 1840; Orthisida- (part), d'Orbigny 1841 
sonidfe, King 1850; Strophomenina' (part), AVaagen 1884. 
David- 
Rafinesquina, Hall 1892. 
Leptsena, Dalman 1828. 
Leptagonia, McCoy 1844. 
Strophomena, Meek 1873 (not 
Blainville 1825). 
Plectambonites, (Ehlert 1887 
(not Pander 1830). 
Stropheodonta, Hall 1850. 
Brachyprion, Shaler 1865. 
Douvillina, GEhlert 1887. 
Leptostrophia, Hall 1892. 
Pholidostrophia, Hall 1892. 
Strophonella, Hall 1879. 
Amphistrophia, Hall 1892. 
Leptella, Hall 1892. 
Plectambonites, Pander 1830. 
Leptania, Davidson 1853; 
(Ehlert 1877 (not Da I man 
1828). 
Tropidoleptus, Hall 1859. 
? Vitulina, Hall 1861. 
Leptffinisca, Beecher 1890. 
Christiania, Hall 1892. 
Davidsonia. Bouchard 1847. 
Subfamily C.vdo.mellin^, Munier-Chalmas 1887. 
Cadomella, Munier-Chalmas 1887. 
Family THECiDiiD^,t Gray 1840. 
Subfamily Thecidiin^, Dall 1870. 
Thecidium, Sowerby 1824. 
Thecidia, Defrance 1822. 
Lacazella, M.- Chalmas 1880. 
Thecidiopsis, M. - Chalmas 1881 
Thecidella, M. - Chalmas 1887. 
Eudesella. M.- Chalmas 1880. 
Pterophloios, Giimbel 1861. 
Bactrynium, Emmerich 1855. 
(In error. Not Bactrillium. 
Herr. ) 
Davidsonella. .M.- Chalmas 
1880. 
*The relative form of the valves in this subfamily, with one exception, Strophonella, 
is tiie rever.^^e of that in the Outhotuetin^. The valves are nearly alwavs one convex 
(ventral), the other concave (dorsal), causing the visceral cavity to he very "shallow. The 
cardinal process is also somewhat differently constructed. 
tThe Thecidiid^ usually are placed with or near tlie Tkuebhatuliu.e. Beecher 
lias shown (Amer. Jour. Sci., vol. xuv, p. 141, 189.J) that their affinities are with the 
etrophomenoids. There are no calcareous brachial supnorts nor deltidial plates in 
Theodium, as are more or less completely developed in all terebratuloids. The charac- 
teristic markings of the dorsal valve are homologous w it\\ t\\o-iQ in Leptienitca, Davhl- 
sonia, and the so-called "reniform markings" of the PRODrcTiD.v.. 
