168 
NAUTILOIDEA. 
men that led Ryckholt into this error may be seen in the Royal 
Museum of Xatural History in Brussels h 
CARBOXIREROrS SPECIES. 
Solenocheilus Caledonictis, Foord. 
[See fig. 30, infra, p. 172.] 
Sp. Char. Shell subglobose, rapidly expanding, composed of pro- 
bably two or two and a half whorls, the section being much wider 
than high. The periphen’ is rather broadly rounded, slightly 
depressed along the median line, and sloping outwards to the edge 
of the umbilicus. Xear the edge of the latter, towards the aperture 
there is a narrow spout-like projection on each side of the shell. 
The septa are moderately distant, except near the body-chamber, 
where the last three or four are crowded together. The siphuncle 
is central. The specimens being all of them casts, nothing is known 
of the test, but the body-chamber has obscure longitudinal lines 
upon it, and there is also a “ normal line ” running down the centre. 
The ventro-dorsal diameter is to the transverse as 17 : 40. 
Beinarh'S. This species finds its nearest ally in Nautilus {Soleno- 
cheilus) Leidyi, Meek and MMrthen -, but the whorls are much wider 
in proportion to their height in the present species, which also has 
a less sinuous form of aperture than Meek and Worthen s shell. 
The latter is known onl}" by a fragment of the body-chamber, the 
siphuncle and test being unknown. 
Horizon. Upper Limestone Group ® (Carboniferous Limestone). 
Locality. Arden Quarry, Xitshill, near Glasgow. 
Eairly well represented in the Collection. 
Solenocheilus, sp. 
This specimen (Xo. 39871) is too imperfect for specific identifica- 
tion. It i‘? the fragment of the body-chamber of a rather large and 
rapidly expanding shell. The periphery is broadly rounded, with a 
very slight depression along the median line, the sides sloping rather 
^ The valves of Chiton occurring in the Carboniferous Limestone have some- 
times been mistaken for the mandibles of a Cephalopod, No fossil mandibles 
(Ehyncholites) have, however, yet been discovered in rocks older than the Trias 
(Muschelkalk). 
^ Geol. Surv. Illinois, vol. v. p. 524, pi. xviii. ff. 2 a, 2 h. 
® For the succession of the rocks of the Carboniferous Limestone series of 
Scotland, see Part I. of the present Catalogue, p. 121 (footnote). 
