The Echinoidea 
of the 
Swedish South Polar Expedition 
by 
Dr. TH. MORTENSEN 
(Copenhagen). 
The collection of Echinoidea brought home by the Swedish South Polar Expe- 
dition does not contain any great number of species. It is, however, of considerable 
importance, affording material for study of most of the Echinoids known from 
the Patagonian-Chilean Region, the Echinoid-Fauna of this Region being, in fact 
especially interesting, from a morphological and biological as well as from a zoo- 
geographical point of view. I have been the more pleased to undertake the working 
out of this collection, as I had contemporaneously undertaken the working out of the 
Echinoidea of the German South Polar Expedition; it was thus a quite exceptional 
occasion afforded to me for studying the Antarctic-subantarctic Echinoid Fauna. 
At the suggestion of Professor NORDENSKJÖLD I have also studied the material 
of Echinoidea collected by the Swedish Expedition to the Tierra del Fuego in 
1 S 95 — 97, and included the results in the present work. This collection had originally 
been entrusted to Professor LUDWIG for study, who, however, most liberally left it 
to me. Though the collection proved to contain only such species as were also re- 
presented in the collection of the South Polar Expedition, it yielded valuable addi- 
tional material for the study of several of the species. — Of material importance 
was further some material of South American Echinoidea entrusted to me for study 
by the Hamburg Museum. 
It was thought necessary to include a few species not represented in the two 
Swedish collections, viz. Abattis Philippii LOVEN and Tripylus excavatus PHIL., on 
account of the interrelations of these species to Abattis cavernosus and Agassizii. 
I — 100133, Schwedische Südpolar-Expedition içoi — içoj. 
