THE BRACHIOPODA OF THE SCOTTISH NATIONAL ANTARCTIC. EXPEDITION. 369 
DESCRIPTION OF SPECIES. 
The literature in the main is restricted to the more important papers. Further 
synonymy will be found in Davipson’s Recent Brachiopoda (1886-1888); FiscHER 
and OFHLERT (1892); and BLocHMaNN (1912). 
Pelagodiscus atlanticus (King). 
Discina atlantica, King, 1868, Proc. Nat. Hist. Soc. Dublin, vol. v. pp. 170-173. 
3 ,, 1880, Davidson, ‘‘ Challenger” Report, pp. 62 and 65, pl. iv. figs. 17-18. 
Discinisca atlantica (King), 1888, Davidson, Mon. Recent Brach., pt. 11. p. 200, pl. xxvi. figs. 18-22. 
5 . 3 1891, Fischer and Oehlert, Haxped. Scient. du “ Travailleur” et du 
** Talisman,” Brachiopodes, p. 120. 
. + 5 Section Pelagodiscus, 1908, Dall, Bull. Mus. Comp. Zool., vol. xliii. p. 440. 
Discinisca , 1911, Eichler, Deutschen S.-P. Maped., xii., Zool., iv. p. 87, pl. xliv. fig. 22. 
Hab.—Station 417 ; lat. 71° 22’ S., long. 16° 34’ W. (off Coats Land, Antarctica). 
Depth, 1410 fathoms. March 18, 1904. Sea bottom, blue mud and _ stones. 
Temperature 29°°9 F. 
Obs.—Four upper valves of this interesting species were trawled at this station. 
The largest specimen measures 6°75 by 6 mm.; the others, 5 by 5, 4°75 by 4, and 3°5 
by 3:5 mm. respectively. 
All are in a good state of preservation. The shell is thin, semi-transparent, 
yellowish-brown in colour, and marked by numerous close-set concentric growth 
lines. The protegulum in each example is well defined, and situated somewhat 
posteriorly. 
Pelagodiscus (formerly Discimsca) atlanticus is a typical cold-water species with 
a bathymetric range from 200 to 2425 fathoms. Its geographic range is almost world- 
wide, as it is known from the North and Mid-Atlantic Ocean, the Pacific, and off 
Australia. Some seven or eight different localities were established for it by the 
Challenger Expedition. 
Off Valparaiso it was obtained by this Expedition in 2160 fathoms, on a mud 
bottom ; temperature 34° F. 
It has also been taken south-west of the Galapagos Islands, in 2035 fathoms ; 
temperature 35°°3 EF’. (Albatross). | 
As mentioned in the prefatory remarks, its probable existence in Antarctic waters 
has recently been alluded to by Er1cHiErR (1911), who describes two larval forms of a 
Discinoid from a depth of about 1640 fathoms, Kaiser Wilhelmland II. These appear 
to have strong athnities with P. atlanticus, and in all probability are referable to this 
widely dispersed form. 
The present discovery of the species well within the Antarctic Circle is highly 
interesting, as it increases the known range to a considerable extent geographically, 
though not bathymetrically. 
