14 
S. s. BUCKMAN, 
(Schwed. Südpolai -Exp. 
Formation: The Pecten Conglomerate. 
Material: Two imperfect (half-grown r) specimens, one smaller, and two quite 
young examples — the smallest about 5 mm in length. 
Family Terebratel lidae. King. 
Sub-Family Magellaninae, Beecher. 
‘Terebratellidæ with the loop composed of descending and ascending branches, 
passing in the higher genera through metamorphoses comparable to the adult struc- 
ture of Bouchardia, Magas, Magasella, Terebratella and Magellania. The lower ge- 
nera become adult before reaching the terminal stages. Recent genera restricted to 
austral seas’ (SCHUCHERT). 
The Antarctic strata have supplied representatives of four of the genera of this 
subfamily — Bouchardia, Magasella, Terebratella = Pachymagas and Magellania. 
Genus Bouchardia, Davidson. 
Till quite recently the only recognised species of this genus was the Recent 
Bouchardia rosea; and no Tertiary species had been recorded. Within the last 10 
years or so, however, various species have been discovered in the Tertiary strata of 
South Ametica and New Zealand. Now, from that portion of the Antarctic which 
is opposite South America, the Swedish Expedition was fortunate to bring home a 
very considerable number of fossil forms of Bouchardia, many of them in such con- 
dition as to show the internal characters. 
The following are the species which have been named: 
B. zitteli, Jhering, Patagonia. 
B. patagonica, » » 
B. tapirina,'^ PIUTTON, New Zealand. 
B. rhisoida, » » 
The series of Antarctic specimens are divisible without much difficulty into at 
least five distinct forms: none of them agree with any species that have been named. 
In a general sense they are intermediate in point of development between the fossil 
species which have been named and the Recent B. rosea — the general course of 
development being from subcircular to elongately elliptical; and the Antarctic spe- 
cies show various steps in such development. 
’ Described by Hutton in 1873 as a Waldheimia. 
