REPORT OH THE FORAMIHIFERA. 
303 
series short and broad. Walls thick ; segmentation complete ; sutural lines generally 
well marked on the exterior. Length, ^th inch (3 '5 mm.). 
Haplophragmium calcareum is probably the largest living representative of the 
genus, and almost equals in dimensions the finest Cretaceous species. The test is mas- 
sively built, the walls thick and composed of coarse sand, often coral detritus or other 
calcareous matter, incorporated by means of an unusual proportion of calcareous cement. 
The species differs from Haplophrcigmium agglutinans in its flattened contour, from 
Haplophrcigmium pseudo spiralis in its distinct and regular segmentation, and from both 
in its large dimensions. 
Under the name Haplophragmium humboldti , 1 Eeuss has described a form which 
serves as a connecting link between Haplophragmium agglutinans and the present 
species. It resembles Haplophragmium calcareum in the compression of the earlier 
portion of the test, and Haplophragmium agglutinans in the nearly cylindrical contour 
of the later segments. 
Haplophragmium calcareum has been found at six Challenger Stations, all of which, 
with a single exception, are within the tropics, namely : — off Culebra Island, West Indies, 
390 fathoms; at two points off the coast of South America, south of Pernambuco, 675 
fathoms and 350 fathoms respectively ; off Kandavu, Fiji Islands, 210 fathoms; Torres 
Strait, 155 fathoms ; and off Sydney, 410 fathoms. 
Haplophragmium tenuimargo, H. B. Brady (PI. XXXIII. figs. 13-16). 
Haplophragmium tenuimargo, Bradv, 1882, Proc. Roy. Soc. Edin., vol. xi. p. 715. 
Test elongate, crosier-shaped, much compressed ; lateral edges thin and jagged. Spiral 
segments few and small ; those of the linear series, about six in number, broad and slightly 
convex ; septation obscure. Aperture simple, irregular in form, terminal. Texture 
coarse, surface extremely rough. Length, T \yth inch (2‘5 mm.) or somewhat less. 
In general appearance Haplophragmium tenuimargo is not unlike Haplophragmium 
pseudospirale, but the test exemplifies a marked advance in structure upon that of the 
latter species, the earlier portion being more evidently spiral, and the cavity definitely 
segmented, though externally the septation is indistinct. Its thin peripheral edge and 
jagged outline are very characteristic features. 
The species has been obtained at six localities, very wide apart, the number of speci- 
mens in each case seldom exceeding two or three. The following is the list: — Faroe 
Channel, warm area, 530 fathoms ; Challenger Station 5, south-west of the Canaries, 
2740 fathoms ; Station 323, east of Buenos Ayres, 1900 fathoms ; Station 218, north of 
1 Originally as Spirolina humboldti, Eeuss, 1851, Zeitschr. d. deutsch. geol. Gesell., vol. iii. p. 65, pi. iii. figs. 17, 18, 
but subsequently as Haplophragmium. 
