294 
NAUTILOIDEA. 
with fine, transverse, angular plications having a direct imbrication, 
and their surface covered with veiy fine transverse lines. 
RemarTcs. The species having the closest affinity with the present 
one are M. debile, Barr,, sp. (pi. clxviii.), and M. parvuhim, Barr., 
sp. (pi. clxxvii.). The former of these is distinguished from M. 
hyhrida by its larger body-chamber, filiform siphuncle, and less pro- 
minent ornaments ; the latter by its greater curvature, and broad 
and nummuloidal siphuncle. 
Eoidzon. Etage E ( = Salopian). 
Locality. Lochkow, Bohemia. 
Eepresented in the Collection by a single specimen. 
Cyrtoceras (Meloceras) insociale, Barraude, sp. 
1867. Cyrtocei'as insociale, Barrande, Syst. Sil. de la Boheme, vol. ii. 
pt. i. p. 666, pi. cxlviii. ff. 10-15, pi. clix. ff. 1-8, pi. clxvi. ff. 6-14. 
Sp. Char. Shell very slightly curved ; upon a chord of 68 millim., 
subtending the concave side, the highest perpendicular is 3 millim. 
The transverse section is nearly circular, but in several specimens 
there is a tendency to assume an oval fonn. The rate of increase 
is variable, but omitting extreme forms it may be taken to be about 
3 in 5. The body- chamber occupies nearly half the length of the 
shell ; it is slightly contracted near the aperture. The latter is 
slightly inclined towards the convex side, upon which there is a 
wide sinus ; a narrower one is found also upon the concave side. 
The distance between the septa is equal to about of the diameter 
of the shell ; they are direct and parallel with the plane of the 
aperture. The siphuncle is situated close to the concave border and 
is cylindrical. The surface of the test is ornamented with very 
fine, irregular, transverse striae, which form a slight sinus upon the 
concave border, in the median line. The striae are grouped in 
irregular bands in some specimens. 
RemarTcs. The species having the closest affinity with the present 
one is M. capidoides^ Barr., sp. (pi. clxvi.), but it is distinguished by 
its more inflated form and proportionately larger body-chamber. 
Horizon. Etage E (= Salopian). 
Locality. Lochkow, Bohemia. 
Eepresented in the Collection by 
Cyrtoceras (Meloceras) Murchisoni^ Barrande, sp. 
1848. Cyrtoceras MurcMsoni, Barrande, Haidinger, Berichte fiber die 
Mittheil. von Freund, der Naturv iss. in Wien, Band iv. p. 209. 
1852. Cyrtoceras Murchisoni, Giebel, Fauna der Yorwelt, Band iii. 
Abth. i, p. 200. 
two) examples. 
