GOMPHOCEE^ TIE 
237 
1882. Gomphoceras "eta, Blake, British Foss. Ceph. pt. i. p. 194, 
pi. xxii. ff. 5, 5 «. 
Sp. Char. Shell pretty strongly curved on the dorsal side, but 
very slightly so on the ventral. Section circular, though in young 
individuals the ventro-dorsal is to the transverse diameter as 12 : 11. 
The rate of increase is about 2 in 5. The body-chamber appears 
to occupy a little less than ^ of the total length of the shell, 
supposing the latter to be complete. Its greatest width is at the 
base, which also represents the greatest diameter of the shell. The 
aperture is strongly inclined towards the ventral side. The larger 
orifice has two pairs of lobes, which are separated from each other 
by a very slight sinus in the adult shell, but in the young the sepa- 
ration is more marked. The channel proceeding from the larger 
orifice is of moderate length, and terminates in a rounded lobe 
which constitutes the smaller orifice. The distance between the 
septa is equal to about -4 of the diameter of the shell. The siphuncle 
is situated at first near the ventral border, but gradually recedes 
to a position nearer the centre as the shell advances ; it is filled 
with radiating deposits. There are only traces left of the test, but 
these show strong transverse striGe of growth. The base of the body- 
chamber is marked upon the cast with very distinct crenulations. 
RemarTcs. On comparing the specimens described by Blake under 
the name of Gomphoceras eta with Barrande’s species, I can find no 
character by which it can be separated from the latter. The biloba- 
tion on each side of the larger orifice of the aperture in Blake’s 
type, though not very distinct, can, nevertheless, be made out. 
The failure to observe this feature doubtless led to the mistake 
as to the affinities of the fossil, 
Blake remarks that the “ general shape of this species is singularly 
like that of G. ohovatum. . . .” 
Horizon. Lower Ludlow. 
Locality. Mocktree, Herefordshire. 
Bepresented by the specimen figured by Blake {loc. cit.) under 
the name of Gomphoceras eta. 
Tetrameroceras infaustum, Barrande, sp. 
1847. Gomphoceras infaustum, Barrande, Haidinger, Berichte fiber die 
Mittheil. von Freunde der Naturwiss. in Wien, Band iii. p. 269. 
1867. Phragmoceras infaustum, Barrande, Syst, Sil. de la Boheme, 
vol. ii. pt. i. p. 224, pi. Iv. 
1877. Phragmoceras infaustum, Barrande, ibid. Suppl. et Serie tardive, 
p. 80, pi. cccclxxxii. ff. 4, 5. 
