GOMPHOCEEATID^. 
231 
middle of the dorsal surface equals about of the ventro-dorsal 
diameter. The siphuncle is generally situated very near the ventral 
border, but it varies a little in position in different specimens ; 
it is filled with radiating deposits. The test is marked only with 
striae of growth. 
Horizon. Etage E ( = Salopian). 
Locality. Eosorz, Bohemia. 
Kepresented in the Collection by a single example. 
Gomphoceras rex, Barrande, sp. 
1867. Phraymoceras rex, Barrande, Syst. Sil. de la Bohenie, vol. ii. 
pt. i. p. 215, pi. Ixi., pi. Ixii., pi. ci. ff. 1-5. 
1858. Gomphoceras rex, Pacht, in G. von Ilelmersen and R. 
Pacht’s Geogn. Untersuch. in den mittl. Gouvern. Russlands, 
p. 78, tab. i. fi‘. 1-4.] 
Sp. Char. Shell large and of robust habit, strongly curved ; the 
apical portion of the shell unknown. Section oval, the ventro-dorsal 
diameter is to the transverse as 11 : 7. The increase in the septate 
part of the shell is in the ratio of 1 : 3 in a length of 50 millim. 
The body-chamber is highly developed, and appears to occupy at 
least one half of the total length of the shell ; it is remarkable for 
the great elevation of the concave side as compared with the convex, 
which is quite the reverse of what is met with in other allied species. 
Hence the angle formed by the plane of the aperture with that of 
the last septum falls beyond the convex side of the shell instead of 
the concave side, as is usually the case. The ventral border of the 
body-chamber is nearly straight, but always a little convex in out- 
line. The larger apertural orifice is elliptical or reniform, of which 
the greater diameter is to the lesser as 5 : 2. The smaller orifice 
forms an ovate expansion at the termination of the channel. The 
distance between the septa increases regularly, and equals t of the 
ventro-dorsal diameter. The siphuncle is situated close to the con- 
cave border of the shell, its elements are nummuloidal, and it is so 
large as to occupy J of the ventro-dorsal diameter ; it is filled with 
radiating deposits. The test has been completely removed by solvent 
action. The general form of the shell, the relative height of the 
body-chamber upon the ventral side, and the great size of the 
siphuncle, serve to distinguish this species. 
Horizon. Etage G ( = Downtonian). 
Locality. Hlubocep, Bohemia. 
Represented by a single very imperfect example. 
