5<S 
TH. MORTENSEN, 
(Schwed. Südpolar-Exp. 
The species was taken by the Swedish South Polar Expedition at Station 3 
(54° 43' S. 64° 8' W. 36 m.), 4 specimens. Further the Swedish Fuegian Expedition, 
1896, has taken 1 specimen in Stewart Harbour, 20 fms., 2 specimens in Fortescue 
Bay, 10 — 12 fms., on bottom with algæ. 
The geographical distribution of the species is the Pacific Coast of South Ame- 
rica, from Tierra del Fuego to Callao (and probably still farther north). On the 
Atlantic Coast it is not known beyond the Magellan Strait. — From other localities 
it has only been recorded from the Philippines, with doubt, in »Revision of Echini» 
p. 162, while in the »Challenger» Echinoidea p. 21 1 this locality is given without 
reservation. That the species does not really occur at the Philippines can not be 
doubted. 
The bathymetrical distribution appears to be very limited, as it is not known 
from greater depths than 85 m. (»Challenger» Ech. St. 304 uStrongylocentrotus gib- 
bositst). It is thus evidently a strictly littoral species. 
The history of this species is rather intricate. Abbé MOLINA in his »Essai sur 
l’histoire naturelle du Chili» (translated from Italian by M. Gruvel 1789 *) gives a 
very poor description of his two species, Echinus albus and niger (p. 175): »Dans 
le genre des oursins il faut d’abord distinguer les oursins blancs et les noirs. Les 
blancs (Echinus albus) sont de forme globuleuse, et d’environ trois pouces de dia- 
mètre, le têt et les piquants sont blancs; la substance intérieure, qui est d’un gout 
excellent, est jaunâtre. Les oursins noirs (Echinus niger) sont de forme ovale, un 
peu plus grands que les blancs, ils ont le têt, les piquants et les œufs noirs, et on 
ne les mange pas.» In a note the following diagnoses are given. Ech. albus: 
»Echinus hemisphærico-globosus, ambulacris denis; areis longitudinaliter verrucosis». 
Ech. niger: »Echinus ovatus, ambulacris quinis, areis muricatis verrucosis». It might, 
indeed, seem quite impossible to recognize from this description the two species now 
identified as Molina’s Echinus albus and niger , viz. Loxechinus albus and Tetra- 
pygus niger ; especially the former has neither the test nor the spines white, as said 
by Molina. Nevertheless it does not appear that Molina’s description could be 
better applied to any other Echinoid commonly occurring at the coasts of Chili, so 
it seems that the interpretation first given in the »Catalogue raisonnée des Échinides» 
by Agassiz & Desor is correct. The correctness of this identification is also indi- 
cated by the description of Echinus albus given (by Blanchard) in Gay’s Historia 
fisica y politica de Chile (loc. cit.) : »E. hemisphærico depresso, obscure pentagono, 
* The Italian Original work »Saggio sulla storia naturali del Chili» 1782, I have not seen; but Dr 
Haktmeyer in Berlin has kindly quoted the place for me, so that I have been able to compare it with 
the translation. 
