MURCHISONIA. 
313 
Fl. exilis, Eichwald, is a small shell which differs in having eight rounded 
whorls with a very broad sinns-band, but is otherwise very similar to this species, 
to which it is just possible that it may belong, ' , 
M. Bachelieri, Rouault, seems from CEhlert's description to be so similar that I 
believe it to be a synonym. The only difference I can see, is the rather greater 
convexity of the upper part of the whorls than in most English examples. M. 
Chalmasi, CEhlert, is identical with some of our varieties. 
I am, on the whole, inclined to regard M. desiderata. Hall, as a plain form of 
the European shell. It comes very close to Goldfuss' figure of M. dilineata, but 
neither it nor any of the other American shells show any signs of sutural nodula- 
tion, and the thin transverse stri^ seem finer and more regular. It appears to 
be at least the American representative form. 
M. intercedeiis, Hall, is another American so-called species which I cannot dis- 
tinguish from some of the smooth examples of the British shell. 
M. obtusangula, Lindstrom, seems so similar in shape that it may be the same 
species. Possibly its sinus-band is rather more elevated. 
Schlotheim's original description of M. turhinata is very vague, and is unaccom- 
panied by a figure. Bronn appears to have been the first to recognise its identity 
with some of the forms {M. intermedia, M. hilineata, M. coronata, M. higranulosa) 
described by Goldfuss, and d'Archiac and de Verneuil. He still separated it 
from M. spinosa which he placed under the name M. binodosa d'Archiac, but as we 
have seen above, there is not the slightest doubt of their identity. The shell was 
figured under the name M. turhinata first by Bronn in 1851 and afterwards by 
F. Romer in 1876, and there can be no question that this is the designation which 
it ought to bear. 
Affinities. — M. Marsi, (Ehlert,^ differs in having a fine line bisecting a broad 
sinus-band ; and M. Lebesconti, CEhlert,"^ and M. Davidsoni, ffihlert,^ differ in having 
very convex whorls and flat sinus-bands. It is very possible that the two former 
belong to a single species ; but I do not think they are varieties of the present shell, 
as their broad and sometimes bisected sinus-bands, combined with broad globose 
whorls, are features which do not characterise any of the varieties of M. turhinata 
which I have had the opportunity of examining. 
The figured specimen of Phillips' original Carboniferous M. angulata* in the 
British Museum is so poor as to be indescribable, but better specimens in the same 
museum show that it is quite distinct. It has a very highly keeled sinus-band 
situated very low on the whorls, and very numerous fine spiral striae. 
1 1887, (Ehlert, ' Bull. Soc. d'Etud. Sci. d'Angers,' p. 17, pi. viii, figs. 1, 1 a. b. 
2 Ibid., p. 18, pi. vii, figs. 3, 3 a, 3 5. 
3 Ibid., p. 20, pi. vii, figs. 4, 4 a — d. 
4 1836, Phillips, ' Geol. Yorks.,' vol. ii, p. 230, pi. xvi, fig. IG. 
