The two very dissimilar _Siliquariæ_ united under this appellation
in the 'Museum Ulricæ,' were originally held distinct. The prickly
variety was the unpublished type, and was thus defined:--
D. ANGUINUM. _D._ spira inæquali angulata aculeata, sulco
longitudinali perforata.
Rumph. 125. t. 41. f. H. Solen anguinus.
Lang. Test. 6. Tubulus vermicularis crista dentata.
Testa albida, teretiuscula, angulis 9 obsoletis. Anfractus inæquales,
nunc confertiores, nunc remotiores. Sulcus longitudinalis in superiore
latere perforatus serie punctorum. Spinæ breves, fornicatæ ad angulos
in latere inferiore.
Condensation, that peculiar faculty of the mental organization of
Linnæus, induced him to suppress this description, and attach the
species, as a variety, to the form he had simultaneously characterized
as _D._ spira elongata, teretiusculum, inerme, fissura longitudinali.
Gualt. test. 10. f. z.
To this latter the published details belong, except the expression
"passim concatenata et quasi poris pertusa" (which was a subsequent
and fallacious addition), and the account of the variety.
S. PENIS. _D._ teres, extremitate radiata disco cylindris poroso.
"Bonan. i. f. 38.", indicated in the tenth edition of the 'Systema',
was among the synonyms. The "Stigma, &c." was an addition; so too were
"lævis," "tubulosis", and "æqualibus". The term "hemisphærico" has
replaced the earlier "convexo."
In addition to the published species, the _S. Spirorbis_ of the
'Systema' appears to have been indicated as