In the original version of the 'Museum Ulricæ,' the members of this
genus are not separated from the _Dentalia_ (a proof, among many
others, of the early date of this catalogue). Linnæus, however,
when revising the transcript, had meditated the withdrawing of _S.
arenaria_ and _lumbricalis_, and constituted for them a nameless genus
with the following definition:--
Testa tubulosa, isthmis concamerata, dissepimentis integris, nec
perforatis, s. communicantibus.
This genus would have been the equivalent of the modern _Vermetus_.
S. TRIQUETRA. _D._ triquetrum, adhærens.
The reference to Gualtieri (whose figure was somewhat uncertain, yet
probably designed for _Vermilia triquetra_) was queried. The proposed
name was _D. parasiticum_.
S. CONTORTUPLICATA. _D._ teretiusculum, depressum, rugosum.
There was at first no name to the description of this shell; but it
was added in the handwriting of Linnæus.
S. GLOMERATA. _D._ teres glomeratum.
The 'decussato-rugosa' of the 'Systema', applicable to the _'Vermetus
subcancellatus_', the shell designed in that work, was not inserted.
Gualtieri's figure is that of _Vermetus glomeratus_, for the colouring
of which 'alba' would be a most inappropriate term.
S. LUMBRICALIS. _D._ spira divaricata teretiusculum, integrum.
D'Arg. t. 29. f. 1. was an additional synonym.
S. ARENARIA. _D._ teres rectiusculum intestiniforme.
Despite the name borrowed from Rumphius, the _Vermetus gigas_ was the
object defined in the tenth edition of the 'Systema'. The absence from
the manuscript of the reference to Gualtieri's drawing of that shell,
and "rectiusculum" in the written diagnosis, confirms the conclusion
previously arrived at, that the _Septaria arenaria_ of authors was
the species intended in the 'Museum Ulricæ': it was subsequently
termed _S. polythalamia_ by Linnæus. The delusive "subangulata" of the
supposititious diagnosis was of course absent.
The _V. gigas_ was probably intended by the following unpublished
description.