106 PERMIAN FOSSILS. 
The genus Schizophoria' 1 propose to typify with the Conch. Anom. resupinatus of 
Martin, and to provisionally characterise it as having an open fissure, often rounded 
umbones, large punctures,” and the valves in general arcuately striated in the cardino- 
lateral regions. The genus thus characterised and typified readily resolves itself 
into a receptacle for most of the shells which M. de Verneuil has included in his 
groups Stnuate, Arcuato-striate, and Plicose? 
Since the period referred to, Mr. T. Davidson, besides rendermg much valuable 
aid as regards the genera just discussed, has thrown considerable light on certain 
shells, the affinity of which were previously mvolved in the greatest obscurity. It is 
now clear, from the figures and descriptions published by this learned brachiopodist, 
that the Anomia biloba of Linneus, and the Terebratulites biforatus of Schlotheim, are 
not Spirifers as they have generally been considered, but species typical of new genera 
allied to the last-described genus, and belonging to the same family,—Strophomenide. 
Impressed with this view, I here take the opportunity of instituting for these shells the 
following two genera. 
Platystrophia,* King.—Type Terebratulites biforatus, Schlotheim. 
Diagnosis—A. Strophomenidia; widest in the transverse direction; tumid; sub- 
eequivalve ; plicated or striated; with large punctures, and a wide bi-areagerous 
hinge. Umbones promment, strongly incurved,. and approximating. Areas with an 
open fissure. Large valve deeply sinuated medio-longitudinally. 
Besides the typical species, this genus embraces Platystrophia Tcheffkini (Spirifer ad.), 
De Vern., P. dentata (Porambonites id.), Pander, P. costata (Porambonites id.), Pander, 
and P. terebratuliformis (Sprrifer rd.), M‘Coy, all of which belong to the Silurian period. 
Dicelosia,’ King.—Type, Anomia biloba, Linneeus. 
Diagnosis—A Strophomenidia ; deeply constricted medio-longitudinally ; striated ; 
widest at its anterior half; ineequivalved; and furnished with a narrow bi-areagerous 
hinge. Umbones slightly gibbous. Area of the large valve with an open fissure. 
The published species of this genus are few im number, and appear to belong 
1 From cxiZw, I split, and gopew, I carry. 
2 The species typical of the genus has a punctated structure. M. de Verneuil’s Schizophoria punctata 
(Orthis id.) possesses this character (vide Bull. Géol. Soc. de France, 2™* série, t. v, p. 35, pl. iv, fig. 8) ; 
and Mr. Morris has noticed it in Schizophoria elegantula (Orthis id), Dalman (vide Geol. Journal, vol. ii, 
p- 389). 
3 It is extremely probable that some of the shells included in these groups belong to uncharacterised 
genera. 
4 From zAarus, wide, and ozpopew, to turn (as a hinge). 
5 From Ses, twice, and korAos, a cavity; in allusion to the shell appearing as if separated into two cavities. 
Brae 
