320 
SUPPLEMENT. 
Orthoceras discrepans^ de Kouinck. 
1844. Orthoceras cinctum, de Koninck, Descrip, des Anim. Foss, du 
terr. Garb, de la Belgique, p. 512, pi. xliii. f. 6, pi. xliv. fF. 5, a, 6, 
pi. xlvii. ff. 3, a, h (synon. excl.), {Not of Sowerby nor of Phillips.) 
1880. Orthoceras discrepans, de Koninck, Faune du Calc. Carbonifere 
de la Belgique, p. 68, pi. xl. flf. 5, a-c. 
8p. Char. Shell straight, rate of increase about 1 in 8 ; transverse 
section circular. Body-chamber not very large, about one fourth the 
total length of the shell. Septa numerous, 1 line distant from each 
other where the diameter of the shell is 5 lines. Siphuncle sub- 
central. Ornaments of the test consisting of very fine, regular, 
direct, transverse raised lines, about four of which are contained in 
the space of 1 line ; between these there are four or five finer striae, 
visible only under a lens. 
RemarTcs. M. de Koninck observes that he originally confounded 
this species with the Orthoceras cinctnm of J. de C. Sowerby, from 
which, however, it is to be distinguished by its smaller size, by the 
sharpness of the rings that ornament its surface, and by its higher 
rate of tapering. From 0. salutatum, de Kon., and 0. salvuni, de 
Kon., it is distinguished by the lesser number of the rings that 
ornament its surface, and by the greater width of the interspaces 
separating them. 
It now becomes necessary to remove 0. cinctum, de Koninck (non 
Sowerby) from the synonymy of 0. cinctum, Sow. (see ante, p. 106), 
where I had erroneously placed it. 
Horizon. Calschiste de Tournai (Assise i. e) ; = Carboniferous 
Limestone. 
Locality. Tournai, Belgium. 
Represented in the Collection by a single example. 
Orthoceras denticulus, de Koninck. 
1880. CyHoceras denticulus, de Koninck, Faune du Calc. Carbonifere de 
la Belgique, p. 21, pi. xxxvi. ff. 11, 11 a, 12. 
Sp. Char. Shell slightly curved at the apex, but straight above. 
Transverse section circular. Rate of increase about 1 in 6. Body- 
chamber not observed. Septa numerous, shallow, nearly equidistant. 
Siphuncle between the centre and the margin. Test apparently 
smooth, or only feebly marked. 
Remarhs. This is a badly characterized species, and may be the 
young of a larger one. 
