230 
NAUTILOIDEA. 
developed. The aperture is very oblique, making an angle of 5(.»° 
with the plane of the last septum. The larger orifice is circular, and 
its diameter equals -| of the thickness of the fossil. The smaller orifice 
projects slightly beyond the concave border of the shell. The channel 
connecting the two orifices is narrow. The distance between the septa 
equals ^ the corresponding ventro-dorsal diameter. The siphuncle is 
near the ventral border ; the form of its elements has not been seen. 
The test is ornamented with fine, slightly projecting striae, having a 
direct imbrication. They are less distinct and less regular than 
those of the allied species G. Brodeiripi ; the very oblique direction 
they take in crossing the shell causes them to be nearly at right 
angles with the septa ; they form a very distinct sinus on the concave 
border of the shell, and a large undulation upon the convex side. 
Eemarics. This species has for its nearest ally G. Brodenjn, which, 
however, has a much greater curvature and a more rapidly expand- 
ing shell, while the aperture is relatively shorter than that of G. 
longum. 
Horizon. Etage E ( = Salopian). 
Localities. Lochkow, Dworetz, Bohemia. 
Fairly well represented in the Collection. 
Gomphoceras pusillum, Barrande, sp. 
1847. Phragmoceras pusillum, Barrande, Haidinger, Berichte fiber die 
Mittheil. von Freund, d. Naturwiss. in AVien, Band iii. p. 269. 
1867. Phragmoceras pusillum, Barrande Syst. Sil. de le Boheme, vol. ii. 
pt. i. p. 220, pi. lii. 
8p. Char. Shell rather small, slightly curved, the dorsal border 
strongly arched, the ventral correspondingly incurved till near the 
region of the aperture, where the shell becomes considerably in- 
flated, so that, upon the whole, it has a pyriform aspect. The 
aperture is almost Y-shaped, owing to the very deep median saddle 
between the two lobes, which constitute the larger orifice ; the 
smaller orifice, which forms only a slightly expanded termination 
to the straight channel, projects a little beyond the ventral border 
of the shell. The transverse section of the shell is oval, the two 
diameters being in the ratio of 4 to 3. The ventro-dorsal diameter 
increases very rapidly at the upper part of the septate portion of the 
shell, so that the latter is very short. The body-chamber occupies 
about one half of the total length of the shell, while its capacity is 
more than two thirds of that of the entire shell. The aperture 
makes an angle of about 60° with the plane of the last septum. 
The septa are very close together, their average distance in the 
