220 
NAT7TILOIDEA. 
spending diameter. The surface of the test bears only striae of 
growth, which appear to be lamellose. 
Horizon. Etage E ( = Salopian). 
Locality. Lochkow, Bohemia. 
Fairly well represented in the Collection. 
Gomphoceras amygdala, Barrande. 
1847. Gojnphoceras amygdala, Barrande, Haidinger, Berichte iiber die 
Mittheil. von Freund, d. Naturwiss. in Wien, Band iii. p. 2G9. 
1867. Gomphoceras amygdala, Barrande, Syst. Sil, de la Boheme, vol. ii. 
pt. i. p. 273, pi. Ixxvii. ff. 23-26, pi. Ixxx. ff. 1-17. 
1882. Gomphoceras amygdala, Blake, British Foss. Ceph. pt. i. p. 198, 
pi. XXV. ff . 4, 4 a, 4 6, ? pi. xxiii. ff . 7, 7 a. 
Sp. Char. In all the specimens of this species one notices at once 
a very marked difference between the dorsal and ventral borders, 
the former being nearly straight, while the latter has a very con- 
siderable degree of convexity. This curvature in the outline ex- 
tends to the body-chamber. The transverse section is an ellipse, 
the ratio of the two diameters of which is as 5 : 6. In some 
examples the section approaches a little more to a circular form, 
especially towards the smaller extremity of the fossil. The body- 
chamber occupies about ^ of the total length of the shell, and in 
bulk it exceeds by more than one half the septate part of the latter. 
The larger orifice of the aperture (whose longer diameter corre- 
sponds with that of the shell) is contracted by the raised dorsal 
border, but it is not recurved ; its breadth is equal to about of the 
transverse diameter. The small orifice is circular and is situated at 
a slightly lower level than the larger one ; it does not project at aU 
beyond the ventral side. The distance between the septa is some- 
what variable in different examples, ranging from 4- to ^ of the 
diameter of the shell. The siphuncle is situated near the ventral 
border, about 4 the distance across the ventro-dorsal diameter ; its 
elements are slightly inflated. The surface of the test has irregular 
striae of growth upon it. 
RemarTcs. Prof. Blake has identified this species from the Lower 
Ludlow of Ledbury, but he observes that “ there is not an absolute 
agreement between our forms and the Bohemian, but the differ- 
ences appear to be within the range of what may be called 
varietal.” 
Horizon. Etage E (= Salopian). 
Locality. Karlstein, Bohemia. 
Fairly weU represented in the Collection. 
