88 
NAimLOTDEA. 
posed, ooly just in contact, and leaving a large central vacuity. 
Section subquadrangular, somewhat inflated laterally, and flattened 
above and below. The ventral side is very broad and perfectly flat, 
the dorsal narrow and scarcely at all impressed by the enveloping 
whorls. The sides, which are about two thirds the breadth of the 
periphery, are a little inflated in the lower third, and slope gently 
inwards towards the periphery, the border of which forms an obtuse 
angle with the sides. The aperture makes a sigmoid curve at the 
sides and is deeply emarginate above. The septa are moderately 
concave, and tolerably near to each other. The siphuncle is situated 
on the ventral side, close to the margin. 
The ornaments of the test consist of flne longitudinal lines which 
appear to be developed only upon the upper half of the sides, and 
upon a limited portion of the flattened periphery. Here (and also 
upon the upper part of the sides) they become stronger and wider 
apftrt, and have one or two still finer lines between them, but they 
disappear altogether at about one fourth the distance across the 
periphery. The longitudinal lines are crossed sigmoidally upon the 
sides by equally delicate transverse ones, and by the intersection of 
the two a very beautiful moniliform ornamentation is produced, 
which, however, can only be seen by the aid of a lens. It is well 
figured by de Koninck (Joc.cit. fig. ^d). The transverse lines form 
a deep sinus upon the periphery, corresponding Avitli the emargina- 
tion in the edge of the aperture. 
Remarks. According to the strict letter of the law of priority, 
Phillips’s name should be adopted for this species, but his description 
and figures are so defective that it would be quite impossible to 
recognize the fossil thereby. Therefore it seems justifiable in the 
interests of science to substitute de Kouinck’s name for that of 
Phillips’s (the two species being clearly identical), de Koninck’s 
figures and description being perfectly satisfactory. 
Horizon. Carboniferous Limestone. 
Locedities. British. Horthumberland? — Foreign. Vise, Belgium. 
Bepresented in the Collection by two examples, one of which is 
the type of Phillips’s species, and is contained in the “ Gilbertson 
Collection.” 
Discites Leveilleanus^ de Koninck, sp. 
1844. Nautilus Leveilleanus, de Koninck, Descrip, des Anim. Foss, du 
Terr. Carbonifm’e de la Belgique, p. 552, pi. xlix. ff . 1, h (pi. xxv. 
f. 1 excl.). 
1849. Nautilus Leveilleanus, d’Orbiguy, Prodr. de Paleont. Stratigr. 
vol. i. p. 110 {non ibid. Paleont. Lbiiverselle, vol. i. pi. Ixxxix.). 
