JTATJTILID^. 
97 
catus, but afterwards adopted Sowerby’s name siilcatas, erasing the 
syllable bi in the plates of the later copies of his work. It is 
quite clear, however, that the name hisulcatus now belongs of right 
to de Koninck, ^‘Coy having rejected it, and indeed it appears 
never to have been printed in the text of his “ Synopsis,” nor was it 
quoted by Griffith (as de Koninck himself says) in his lists of Irish 
Carboniferous Fossils h 
Horizon. Calcaire Carboniftu’e Supm’ieur de Vise (Assise vi.), 
= Carboniferous Limestone. 
Localities. British. Craven, Yorkshire ; HesketKewmarket, Cum- 
berland. — Foreign. Vise, Belgium. 
Eepresented in the Collection by several imperfect specimens. 
Discites ? involvens, Salter, sp. 
1865. Xantilus? involvens, Salter, in Palaeontology of Niti in the 
Xorthem Himalaya, being Descriptions and Figures by J. W. 
Salter and H. F. Blanford of the Palaeozoic and Secondary Fossils 
collected by Colonel E. Strachey, E.E., p. 12, pi. ii. f. 3. 
Sp. Char. “ X. involutus, compressus, anfractibus 3 latis, ad 
umbilicum parvum valde rotundatis, lateribus planis, angulis ex- 
ternis obtusis, dorso piano. Septa obliqua conferta, lente curva, 
nisi ad umbilicum abrupte flexa. 
“The name Xautilus is retained for this obscure fossil rather as 
an indication of its possibly belonging to a newer set of rocks [than 
Silurian]. It is too involute and Xautiloid for any Silurian Lituites 
or allied genus known to mo, but is not unlike some of the species 
of Discites, a subgenus of Xautilus common in Carboniferous 
strata. 
“ Our specimen has a diameter of 2^ inches, and has three com- 
pressed whorls — perhaps a minute fourth. The outer whorl is 
nearly four times as wide as the next succeeding, and is swelled 
and abruptly rounded near the umbilicus, then flat on the sides, 
and bluntly angular between these and the back. This is flat, and 
has a greater width than our crushed specimen would at first indi- 
cate. . . . The surface is destroyed. 
“The septa are very oblique forwards, bent sharply over the 
umbilical slope, then sweeping forward in a low curve over the 
^ “ Notice respecting the Fossils of the Mountain Limestone of Ireland as 
compared with those of Great Britain, and also with the Devonian System/’ 
1842, p. 20. 
PAUT II. H 
