240 
NAUTILOIDEA. 
septum. The pair of lobes in the larger orifice, nearest the dorsal 
margin, are considerably longer than the other pair, and are separated 
from them by a very wide sinus. The smaller orifice, which is of an 
elongate-oval form, is connected with the larger one by a somewhat 
narrow channel. The whole aperture is like the letter T, with two 
shorter arms below the longer ones, pointing backwards (see fig. 36). 
Fig. 36. 
d 
Outline of the aperture of T. veins, Barr. sp. Beduced from Barrande’s 
figure, pL liv. f. 4. d, dorsal margin ; v, ventral. 
The septa are distant about of the ventro-dorsal diameter of the 
shell. The siphuncle is situated at a distance from the ventral 
margin equalling about | its own diameter, a distance which is 
maintained pretty constantly throughout the whole length of the 
shell. Its width does not exceed of the ventro-dorsal diameter ; 
its elements are nummuloidal, and it is filled with radiating deposits. 
The test is ornamented with lines of growth which tend to form 
raised, thread-like lines, and follow the contour of the orifices of the 
aperture. Besides the transverse lines, there are sometimes very 
fine longitudinal ones, chiefly upon the sides of the shell ; these 
can only be seen in a good light. The base of the body-chamber is 
crenulated, and a series of faint longitudinal bands are visible upon 
the cast. These bands are apparently connected with the crenu- 
lations. 
RemarTes. This species fi^ds its nearest ally in T. infaustum, but 
it differs from this and others of its congeners by the characters of 
its aperture, in which the lobes of the larger orifice are usually 
wide apart. T. vetus forms one of a group of which the species 
strongly resemble each other ; these are T. Loveni, T. discrejpam^ 
T. insolitum, T. hicinctum, and T. infaustuni. 
Horizon. Etage E ( = Salopian). 
Localities. Kosorz, Lochkow, Bohemia. 
Fairly well represented in the Collection. 
