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 Echir.oid- 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 

 1895 — 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. Abatus Philippii LovÉN and Tripylus excavatus PHIL., on 

 account of the interrelations of these species to Abatus cavernosus and Agassizii. 



I — lOOUiS. Schwedische Südpolar-Expedition igoi — içoj. 



