ANOMIA. 135 
Wenlock Formation.” (Sharpe MS.) ‘It is a true Orthis, as 
I showed many years ago.” (Davidson MS.) 
Anomta placenta. 
This Placuna (for the modern genus is not doubtful, since 
all the cited figures represent members of that little group) 
comprehends more than one species in its synonymy. Lister 
(the necessary circuitous style of reference to whose first and 
imperfect edition has been changed to 225, its modern equiva- 
lent, in the revised copy of the ‘ Systema’) exhibits P. placenta, 
but with the dorsal edges almost as little sloping as in P. 
papyracea, which last is the shell figured by Gualtier. Seba’s 
plate, which was not quoted in the tenth edition, contains both 
of these, and P. sella besides. Thus no less than three out of 
the four known Placune are included by the synonymy, and as 
the term “ orbiculata” was not formerly used in so restricted a 
sense as at present, and the colouring is not mentioned in the 
‘ Systema,’ all these would, perchance, have alike merited the 
name placenta, had it not been for the details mentioned in the 
‘Museum Ulrice,’ where the decided inequality of the teeth in 
length being expressly stated, confines the name to the P. pla- 
centa of authors solely. And this is the shell (Crouch, Introd. 
Lam. Conch. pl. 12, f. 11) which has been marked for the species 
in the Linnean cabinet. 
The “ cardo rufescens” of the twelfth edition of the ‘ Sys- 
tema’ is scarcely intelligible to me. 
Anontta sptiosa. 
Not being sufficiently conversant with fossil species, I have 
sought the aid of our highest authorities on the subject. Mr. 
Davidson, who in knowledge of the Brachiopodes is second to 
no man breathing, has thus succinctly answered my inquiries : 
“T believe, from the very vague data given by Linneus, that 
the Rhynconella spinosa (Knorr, Lap. Diluvii, pl. B, 4, f.4) was 
the species he designed. For it is a common English Oolitic 
