48 
N-AT7T1L0IDEA. 
examples, has a length representing at least from 4 to 5 times the 
diameter of its base. The distance of the septa is about 3 the dia- 
meter. The siphiincle is cylindrical and a little eccentric, but \rith 
some part of it always touching the central axis. The surface 
ornamentation commences in the young shell with very distinct 
annulations, but these disappear in the adult, and irregular rugosities 
take their place, the whole of the test being covered with irregular, 
rough, raised lines. 
Remarks. The most striking feature in this species is the diversity 
of the surface ornamentation in different parts of the same shell. 
The species attains a considerable size, specimens having been col- 
lected exceeding three feet in length. 
0. inchoatum differs from 0. subannulare, 0. Duponti, and others 
of its congeners, by the irregularity of its ornamentation in the 
adult state. 
Horizon. Etage E, bande e2 ( = Salopian). 
Locality. Hinter-Kopanina, Bohemia. 
Fairly well represented in the Collection. 
Orthoceras Nicholianum, Blake. 
1882. Orthoceras Nicholianum, Blake, British Foss. Ceph. pt. i. p. 88, 
. pi. hi. ff. 7, 7 8, lo. 
Sp. Char. Section unascertainable, owing to compression. Bate 
of increase slow, but its amount unknown. Septa estimated, by the 
remains of the beaded siphuncular elements, to be distant about | 
of a line. Body-chamber unknown. Siphuncle apparently central. 
Surface ornaments consisting of “ transverse, sharj), scarcely sepa- 
rate ribs, with an obliquity of about 5° and about ^ the diameter 
apart. These are crossed by sharp, separate, longitudinal lines, 
which pass over the ribs and slightly knot them at the crossing. 
They are irregularly placed and not all of the same size ; on the 
whole they are about three or four times as numerous as the ribs. 
Besides these, there are extremely fine transverse lines five times 
as close as the longitudinal, and scarcely parallel to the ribs.” 
Remarks. The specific name Nicholianum was adopted by Pro- 
fessor Blake from the type specimen in the Museum at Cardiff. 
Horizon. Wenlock Shales (Salopian). 
Locality. ? Dudley, Worcestershire. 
Well represented in the Collection. 
