216 MR. J. W. KIRKBY ON SOME FOSSILS FROM THE 
portion being flat, and the lower portion widely umbilicated. 
The whorls are subangular, increase rapidly in size, are margined 
superiorly by a prominent keel externally, and by a narrow 
sulcus or channel internally. The surface is densely marked with 
fine transverse striz. The largest specimens are ;°,ths. of an 
inch in width and ,2,ths. in height. 
This is the most common of the fossils that occur. Nearly 
all the specimens are impressions, only one or two being casts. 
When this species was first discovered in Germany, it was 
referred to the genus Huomphalus by Count Miinster. It was 
afterwards removed from the Gasteropoda, and described as a 
Serpula, by Dr. Geinitz.“> Baron Von Schauroth, of Coburg, 
next replaced it among the gasteropods in the genus Straparollus, 
of which Euomphalus is a synonym.‘?> Since then Dr. Geinitz 
has again figured and described it, but still as an annelid of the 
genus Serpula.® 
So far as my own pinion is concerned, I can only say that I 
see nothing that appears to support Dr. Geinitz’s views as to 
the affinities of this fossil.‘4? Its general habit is that of a 
gasteropod ; and it is apparently correctly placed by Miinster 
and Schauroth in the genus Séraparollus. Indeed, there is so 
great a resemblance between it and a common carboniferous 
species — Straparollus carbonarius—that I am almost persuaded 
they are the same. 
As a British fossil S. planorbites has not previously been 
noticed in Permian strata. On the Continent it occurs in various 
localities in the Mergelschiefer, Unter Zechstein, and Zechstein 
Dolomit. 
3. Chiton Loftusianus? King. Catalogue Org. Rem. Perm. Rocks 
|g Be 
Two specimens that appear to belong to this species have 
occurred. One is a single anterior plate, 3th of an inch in width. 
(1) Deutsch. Zechst. p. 6, pl. 3, figs. 1 & 2. Mm 
(2) Zeitschr. d. Deutschen Geolog. Gesell. Jahrg. vol. viii. (1856), p. 235, pl. xi. fig. 6. 
(3) Dyas, vol. I. p. 40, pl. x. figs. 10-14. a ; ‘ 
(4) It may further be observed that Dr. Geinitz has included in his list of synonyms 
of this species a true annelid, which has been described by Mr. Howse and Professor 
King under the names of Spirorbis globosus and Spirorbis helix. ‘This fossil, like the 
recent Spirorbis, is always found attached to foreign substances, such as the valves of 
Producta horrida, Monotis speluncaira, and other shells. It is also far more minute than 
Straparollus planorbites, to which it has been wrongly referred. 
