CYET0CERAT1D.5:. 
295 
1867. Cyrtoceras MurcMsoni^ Barrande, Sjst. Sil. de la Boheme, vol. ii. 
pt. i. p. 6S7, pi. cxlTiii. ff. 7-9, pi. clx. fE. 10-19, pi. cIxy. fE. 8-20, 
pi. clxxvi. fE. 5-12, pi. cc. ff. 9-12. 
Sp. Char. Shell very strongly curved, without, however, forming 
a complete whorl. The transverse section is oval, the narrower 
extremity corresponding with the concave border of the shell. The 
ratio between the two diameters varies from 4 to 3 to 11 to 9. 
The rate of increase of the shell is also subject to variation; it 
averages 1 in 3, measured in the septate part of the shell. The 
body-chamber occupies between ^ and f of the total length of 
the shell, and its capacity equals that of the septate part. The 
aperture is parallel to the plane of the last septum. The distance 
between the septa does not exceed the diameter of the shell, 
their concavity equals about | of the same. The siphuncle is close 
to the concave border of the shell ; it is composed of flattened 
nummuloid segments, much constricted at the necks of the sexfla, 
and being more expanded above than below. The test is ornamented 
with irregular lines of growth, which sometimes develop into 
plications ; they cross the sutures of the septa obhquely with their 
convexity turned towards the aperture, making a well-marked sinus 
in the median line of the concave border, but only a very slight 
inflexion on the convex side. 
Remarlcs. The species having the closest affinity with M. Mur- 
chisoni are J/. Beaumonti, Barr., sp. (j)l. clxv.), and M. neutriim^ 
Barr., sp. (pi. clxv., pi. cc.) : the former is distinguished by its more 
raj)id expansion, conjoined with a stronger curvature, and the 
siphuncle being filled with lamellae of a peculiar appearance ; the 
latter by its elongated and more slender form. 
Barrande comx>ares the present species with Phragmoceras arcu- 
atum, J. de C. Sowerby (Murch. Sil. Syst. jd. x. f. 1) ; but as the 
latter belongs to a different genus, there can be no relationship 
between the two. 
Horizon. Etage E ( = Salopian). 
Localities. Konieprus, Lochkow, Butowitz, Dlauha Hora, Bohemia. 
Well represented in the Collection, 
Cyrtoceras (Meloceras) quasi-rectmn, Barrande, sp. 
1848. Cyrtoceras quasi-rectum, Barrande, Haidinger, Berichte fiber die 
Mittheil. von Freund, der Natiirwiss. in Wien, Band iv. p. 208. 
1852. Cyrtoceras quasi-rectum, Giebel, Fauna der Vorwelt, Band iii^ 
Abth. i. p. 209. 
1867. Cyrtoceras quasi-rectum, Banande, Syst. Sil. de la Boheme, 
