66 
rather diverging from an imaginary central line towards both 
the inner and outer surfaces, as shown at fig. 4, and partly 
in fig. 3. When several of the coats are broken off the ex- 
posed portions of those remaining have the appearance of 
trumpet-shaped tubes inserted into one another, as may be 
seen in figures 2. and 3 : a longitudinal section, that is, in 
the direction of the axis of the shell, shows fibres perpendi- 
cular to the surface, as round the aperture in fig. 1 : this 
structure was first pointed out by Mr. Lonsdale, who had 
a portion (fig. 4.) polished in which the variation of colour 
assists in developing the thickness of the layers. A similar 
structure may be traced, less readily, in Euomphalus. The 
edge of the mouth has a slight sinus, formed by the project- 
ing keel that runs round the spire upon the whorls ; it is 
otherwise even, and is continued over the preceding whorl ; 
it is placed more perpendicularly than in Euomphalus pen- 
tangulatus ; in old subjects it becomes elliptical and trans- 
verse. A few obscure furrows may be observed along the 
whorls, and add somewhat to the rugosity of their upper 
parts ; the base and the umbilicus are particularly smooth. 
In old shells septa are formed which separate the smaller 
whorls, as in many other spiral shells, especially in Euom- 
phalus. 
This appears to be an abundant shell near Kendal ; our 
figure 3. is taken from a portion of one sent me by the Rev. 
Mr. — Fisher from that place, and several fine specimens 
from the same locality are preserved in the University 
Museum at Cambridge. Fig. 1. is from the best individual 
in Mr. Gilbertson’s collection, at the British Museum ; 
fig. 2. from Settle in Yorkshire ; and fig. 4. a section made 
by Mr. Lonsdale of a fragment from Ireland, placed in the 
cabinet of the Geological Society by the Earl of Ennis- 
killen. It also occurs in Northumberland and other places 
in the middle and lower beds of the carboniferous lime- 
stone. 
Cirrus acutus, tab. 141. f. 1, is distinguished by the form 
of the upper portion of the whorl. 
