Spire- Bearing Br-achiopoda. — Schuchert, 
105 
A. Subfauiil} T Sl'essiix.k, Waagen 1883. 
Loop a continuous, more or less V-shaped band. 
Cyrtina, Davidson 1858. Spiriferina, d'Orbigny 1N17. 
Thecocyrtella, Bittner 1892. Suessia, Deslongchamps 1K54. 
Cyrtotheca, Bittner 1890 (not 
Salter). 
Subfamily Uncitixj;, Waagen 1883. 
Loop as in Suessiince. Just within the posterior margin 
of the dorsal valve are pouch-like plates. Deltidial plates 
united, deeply concave. Subfamily anomalous. 
Uncites, Def ranee 1825. | ? Uncinella, Waagen 1883. 
B. Subfamily Tiugonotketin.e, Schuchert 1893. 
Delthyrinae (part), Waagen 1883. 
Loop at maturity largely absorbed medially, being then rep- 
resented by two processes, one attached to each primary 
lamella. 
? Cyclospira, Hall and Clarke 
1893. 
Spirifer, Sowerby 1815. 
Choristites, Fischer, de Wald. 
1815. 
Trigonotreta, Koenig 1825; 
Meek and Hayden 1864. 
Spiriferus, Blainville 1827. 
Spirifera,J.de C. Sowerby 1835. 
Brachythyris, McCoy 1814. 
Fusella, McCoy 1844. 
Hysterolithus, Quenstedt 1871. 
Syringothyris: Winchell 1863. 
Spirifer, Meek and Hayden 
1864. 
Delthyris, Dalman 1828. 
Murtinia, Waagen 1883. 
Martiniopsis, Waagen 1883. 
Mentzelia, Quenstedt 1S71. 
Ambocoelia, Hall I860. 
Reticularia, M<-( !oy Is4 i. 
Verneuilia, II. and <'. 1893. 
? Metaplasia. II. and C. L893. 
Cyrtia, Dalman 182s. 
TIL Family ATHYRID/C, Phillips 1841. 
Nucleospirida?, Davidson 1882; Koninckinida*, Davidson 1853. 
Primary lamellae situated between the spirals, and sharply 
recurved dorsally al their junction with the crura. Spirals 
more or less laterally directed. Loop complete, V-shaped, the 
apex being always drawn out into a simple, bifurcated, or 
otherwise terminally modified, process. 
A. Subfamily Rhynchospirin^e,* n. subfam. 
Retziina, Waagen 1883. 
The single process of the loop commonly sharply recurved, 
*Since Retzia does not express the characters of this subfamily as 
well as Rhynchospira does, Waagens term Retziina is here abandoned. 
