HELIX. 365 
which, moreover, neither “latere acuto” (a sharp periphery) 
nor “apertura—duplo latiore quam longa” can be truly affirmed. 
Judging from these expressions, from the “ Testa convexa quasi 
ex uno contiguo,” and from the illustrative figure in Gualtier, 
I cannot but suspect that one of the large Carocolle (probably 
aged and decorticated) was the original of this description. 
The C. angistoma delineated in the last-named work does not 
display the white surface and the patulous reflection of the 
outer lip required by the ‘ Systema.’ 
Helix vortex, 
The correctness of the synonymy and the description of this 
shell in the ‘ Fauna Suecica’ have established its identity with 
the Planorbis vortex of modern systematists. This shell (Tur- 
ton’s ‘ Manual of the Land and Freshwater Shells of the British 
Islands,’ fig. 91) forms part of the Linnean collection, and alone 
of those present in the cabinet agrees with the language of our 
author and the figures he has cited. The manuscript of the 
younger Linné contains additional and corroborative references 
to “ Pet. Gaz. t. 92, f. 6.—List. Conch. t. 138, f. 43.” 
Helix scabra, 
Our author having recorded his possession of this Helix, no 
reasonable doubt can be entertained that the shell, which alone 
of his collection agrees with the description, should be regarded 
as the type. Itis the Littorina scabra of modern conchologists, 
and was described and delineated by Chemnitz (Conch. Cab. 
vol. xi. pl. 210, f. 2074, 2075) under the Linnean name; that 
author having happily guessed at a species, which was neither 
defined by an adequate diagnosis nor illustrated by a reference 
to any engraving. It was probably included, too, in the Pha- 
sianella angulifera of Lamarck, but the limits of the latter can 
scarcely be ascertained, so very closely do the numerous 
varieties of Littorina scabra and L. angulifera (even with the 
amended definitions of Philippi) approach each other. 
