280 
NATJTILOIDEA. 
the shell. The siphuncle is placed near the margin of the shell on 
the convex side. The test is thick ; it is ornamented with very pro- 
minent transverse, imbricating plications, which become extremely 
coarse in the upper part of the shell, forming sharply angular ridges ; 
the whole is covered with fine transverse lines. 
Bemarhs. This species is distinguished from others of the same 
group by its general form and by its characteristic surface orna- 
ments. 
Horizon. Etage E ( = Salopian). 
Locality. Lochkow, Bohemia. 
Well represented in the Collection. 
Cyrtoceras (Meloceras) nuntius^ Barrande, sp. 
1867. Cyrtoceras nuntius, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 606, pi. cxli. if. 7-15, pi. ccii. ff. 5-13. 
1877. Cyrtoceras nuntius, Barrande, ibid. Suppl. et S^r. tardive, p. 162, 
pi. dxvi. fi*. 12-15. 
Sp. Char. Shell moderately and uniformly curved. Upon a chord 
of 50 millim., subtending the concave side, the highest perpendicular 
is 5 millim. The transverse section is oval, the smaller extremity 
corresponding with the convex side of the shell, which is here slightly 
carinated. The ventro-dorsal is to the transverse axis as 7 : 6. The 
rate of increase in the septate part of the shell is in the ratio of 4 
to 5, in a length of 20 millim. The body-chamber occupies about 
I of the total length of the shell in adults. The distance between 
the septa increases slowly and scarcely exceeds yL of the ventro- 
dorsal diameter ; about 40 septa may be counted in the entire shell. 
The siphuncle is placed upon the convex border of the shell ; it is 
a little inflated between the septa. The surface of the test presents 
fine, irregular, trans'f^erse lines of growth. 
BemarTcs. One of the nearest allies of the present species is M. 
fortunatum, Barr. (pi. cxiii.), but it is a thicker shell with a more 
rounded section, and its test is ornamented with crenulated striae. 
Horizon. Etage E, bande el (= Salopian). 
Locality. Butowitz, Bohemia. 
Eepresented in the Collection by a single example. 
Cyrtoceras (Meloceras) plebeium^ Barrande, sp. 
1848. Cyrtocefi'as plebeium, Barrande, Haidinger, Berichte fiber die 
Mittheil. von Freund, der Naturwiss. in Wien, Band iv. p. 209. 
1852. Cyrtoceras plebeium, Giebel, Fauna der Vorwelt, Band iii, 
Abth. i. p. 209. 
