ANIMALS. 93 
Genus Strophalosia, King, 1844. 
Sponpyivus (Gotprusst), Miinster, 1839. 
Ortuis (Excavata), Geinitz, 1842. 
StropHaLosta (= Leprmnatosia), King,! 1844. 
Propuctus, de Verneuil, 1845. 
(?) AuLosteGEs, Helmerson, 1847. 
OrTHOTHRIX Gentz, 1848. 
Diagnosis —A Productidia having the large valve (occasionally the small one) 
furnished with an area divided by a deltidium ; and both valves articulating by means 
of teeth and sockets,—the former situated on each side of the base of the deltidium of 
the large valve, and the latter on each side of the éoss or cardinal muscular fulcrum 
of the small valve. 
Type, Orthis excavata, Geinitz—=Strophalosia spinifera, King? 
In a paper published in the ‘Annals and, Magazine of Natural History,’ for 
November 1844, 1 announced my intention of instituting the present genus “for a 
Productus-like shell with an area, and possessing a condyloid (condyliferous) hinge, as 
in Terebratulee, and not a simple one, as in the true Producti:” and in my paper 
on the ‘Palliobranchiata, subsequently published in the same journal, I entered 
“into some details on this group, showing its distinctiveness, and how it differed from 
Productus, a closely-allied generic form. Since the last paper appeared, Colonel von 
Helmerson’ has proposed the genus Awlosteges for a singular shell (named by himself 
A. variabilis) occurring rather abundantly in the Permian limestones of Mount Grebeni 
in the North of Orenbourg, Russia, and which is now known to be identical with 
M. de Verneuil’s Orthis Wangenheimi. Colonel Helmerson considers this genus to be 
distinct from my Sfrophalosia ; but I regret that its principal distinctive features are 
not so clearly shown as could be desired. The presence of spines on the deltidium* 
constitute, in my opinion, the only distinctive character; but I am not prepared 
positively to deny the existence of deltidial spmes in Strophalosia, though, with the 
exception of some obscure indications (in the form of irregular risings on the deltidium) 
in S. Goldfussi, they do not appear to be characteristic of the species herein described. 
1 The name Leptenalosia, a mere provisional MS. name noticed in the Ist vol. of the Geology of Russia, 
was shortly abandoned for the one now adopted. 
2 Vide Annals and Magazine of Natural History, vol. xviii, p. 28. 
3 « Aulosteges variabilis, ein neuer Brachiopode mit articulirtem Schlosse, aus dem Zechstein Russlands,”’ 
von G. Von Helmerson; Lu le 22 Janvier 1847: and published in the Bulletin de la Classe Physico- 
Mathématique de I’ Académie des Sciences de St. Petersbourg, t. vi, No. 9. 
4 Mr. T. Davidson assures me, that both he and M. de Verneuil, from an examination of specimens in the 
latter gentleman’s collection, are convinced that spines do exist on the deltidium of dulosteges variabilis 
= Orthis Wangenheimi, a character of which I have hitherto entertained some doubt. 
