516 
THE YOYAGE OF H.M.S. CHALLENGER. 
terminal neck, with annular or spiral raised ornament and phialine or cleft lip. Length, 
jigth inch (17 mm.). 
In the general form of the test and the disposition of the chambers there is little to 
distinguish this species from some of its congeners, but the minute structure of the shell- 
wall of the later segments displays certain remarkable features. 
The normal Nodosarian shell consists of a homogeneous and finely tubulated 
calcareous lamina ; but the present species exhibits, in addition to this primary 
investment, a supplementary, external, cellulated layer. The structure is perhaps best 
explained by supposing it to have originated in a costate Nodosarian shell, in which the 
furrows between the ribs had been covered over, and the passages so formed subdivided 
by cross partitions. The actual condition of the shell-wall is readily understood from 
the transverse and longitudinal sections figured in the accompanying woodcuts. The 
transverse section (fig. a) shows little beyond the primary investment with its 
minute tubulation, and the exogenous costse ; for, owing to the extreme tenuity of the 
external covering, it has been almost entirely lost in the process of grinding. But in 
the longitudinal section (fig. b), which is much more highly magnified, the supplementary 
structures are better preserved ; and not only are the 
outer film, and the partition-walls dividing the inter- 
costal furrow into cells, shown in situ, but the pores by 
which the cells communicate with the exterior are also 
clearly defined. Owing to its soft spongy texture, the 
external layer is easily broken away, without injuring 
the more solidly constructed investment underneath ; 
and it was the occurrence of specimens in the abraded 
condition represented in PI. LXY. fig. 4, that first 
directed attention to the anomalous character of the 
shell. 
There is an obvious similarity in structure between 
the test of Nodosarici intevcellidaris and that of 
Lagena hertwigiana described on a former page, the 
chief difference being the greater thickness and the well-marked tubulation of the primary 
wall of the former. Dr. Schwager has figured (Novara-Exped., geol. Theil, vol. ii., pi. v. 
fig. 26) what appears to be a single chamber of the present species, under the impression 
that it might belong to the genus Ovulites. The structural resemblance of these forms 
to some of the Dactyloporidce is in many ways remarkable, the more so as recent 
researches tend to show that it is purely accidental. 
Nodosarici intercellularis has only been found at one locality, namely, — Station 33 
off Bermuda, depth 435 fathoms. 
Fig. 15 . — Nodosaria intercellularis. 
a. Transverse section of the shell, magnified 
200 diameters. 
b. Longitudinal section, magnified 400 
diameters. 
