GOMPHOCERATID^. 
235 
aperture, but below this they are at a greater distance from each 
other, that is about 3 lines apart where the diameter of the shell 
is 2-L inches. Nothing of the test remains, but the base of the 
body-chamber is marked with crenulations, and these extend to 
some of the septa contiguous thereto. The dimensions of the 
specimen are : — Greatest length 3| inches : greatest breadth, mea- 
sured ill the plane of the longer diameter, 2f inches. The siphuncle 
is not preserved. The specimen figured by Pacht appears to have 
been distorted, as it is, if a GompJioceras, of very abnormal shape, 
the septate part narrowing towards the body- chamber instead of 
becoming wider, the body-chamber being apparently of a cylin- 
drical form. The resemblance is by no means remote between the 
present specimen and Gom'phoceras compressum, Koemer \ but in 
the latter the septa are much closer together. 
Horizon. Devonian. 
Locality. Jelez, Russia. 
Genus TETRAMEROCERAS, Hyatts 
{Tetrameres, Tetramorion, Barraude, 1867^.) 
Fig. 35. 
ff 
Outline of the aperture of Tetrameroceras, showing the two pairs of lobes in 
the larger orifice. Reduced from Barrande’s figure, plate li. f. 3. d, 
dorsal margin ; v, ventral. 
Gen. Char. This genus differs from solely in possess- 
ing two pairs of lobes in the larger orifice of the aperture, instead 
of one pair. Its stratigraphical range is limited, so far as is known, 
to the Silurian epoch. Type, Tetrameroceras \_Phragm.'] hicinctum., 
Barr. (pi. li.). 
^ PaljEontographica, Band iii. 1854, p. 4, tab. i. ff. 7 a, h. 
^ Proc. Boston Soo. Nat. Hist. vol. xxii. 1883, p. 277. 
s Syst. Sil. de la Bohdme, vol. ii. pt. i, pp. 203 & 265. 
