REPORT ON THE FORA MINIFER A. 
335 
Kerguelen Island, 1570 fathoms ; off Kerguelen, 120 fathoms; at five points in the South 
Pacific, 345 to 2425 fathoms ; and at two in the North Pacific, 50-150 fathoms and 2575 
fathoms respectively. 
The earliest geological appearance of the species is in the Jurassic beds of Canton 
Aargau, Switzerland (Haeusler). As a Tertiary fossil it is figured by Karrer in his 
memoir on the older Vienna Sandstones, and by von Schlicht in his work on the 
Septaria-clay of Pietzpuhl, in North Germany. 
Ammodiscus shoneanus, Siddall (PI. XXXVIII. figs. 17-19). 
Trochammina shoneana, Siddall, 1878, Proc. Chester Soc. Nat. Sc L, pt. 2, p. 46, figs. 1, 2. 
Ammodiscus shoneanus, Id. 1879, Catal. Brit. Rec. For., p. 5. 
„ „ Balkwill and Wright, 1882, Proc. R. Irish Acad., ser. 2, vol. iin 
(Science), p. 546. 
“ Test spiral, subcylindrical, slightly tapering, narrow end rounded [or sometimes 
sharply conical] ; composed of a single series of close convolutions of a non-septate tube 
on a linear axis. Sutural line more or less depressed externally. Aperture large, 
rounded ; formed of the end of the tube, somewhat constricted. Texture finely 
arenaceous, colour light brown to rusty red. Length, y^tli [to ^th] inch [0'25 to 
0’5 mm.].” 
“ This form is closely allied to Trochammina gordialis and Trochammina charoides. 
It differs from the former in its elongate regular habit of growth, and from the latter in 
the extension of the convolutions lengthwise in single series, instead of their superposition 
in several layers.” 
With the exception of the few words in brackets, the foregoing description and 
remarks are quoted from Mr. Siddall’s interesting paper on the Foraminifera of the River 
Dee {loc. cit .) In connection with the trifling additions which have been made to the 
text, it may be explained, that whilst the Challenger specimens agree in all important 
points with those from the British coast, many of them, especially such as are of large 
dimensions, have the inferior end of the test slightly swollen and pointed. The maximum 
size is set down in the original description as -g^th inch, but amongst specimens from the 
Southern Ocean -gVth inch is not an unusual length. 
Ammodiscus shoneanus was first obtained from shallow water at Hilbre Island and 
Holywell, in the estuary of the Dee (Shone, Siddall), and has since been taken off Slieve 
League, South Donegal (Wright), and in Dublin Bay (Balkwill and Wright). The two 
Challenger Stations at which it has been found present considerable contrast to these in 
latitude and depth; they are, off Christmas Harbour, Kerguelen Island, 120 fathom's; 
and Station 238, in the very deepest part of the North Pacific, 3950 fathoms. 
