Some new species of Echinoidea. 
By 
Dr. Th. Mortensen. 
Åmong the Echinoidea collected by the ”Ingolf”- Expedition, 
the German and the Swedish South-Polar. Expeditions I find some 
interesting new species. Since the publication of the final reports 
on these collections will be somewhat delayed on account of my 
absence from Europe this winter, I take the occasion to publish 
here a short preliminary notice of these species, viz. Urechinus 
Drygalskii, from the German South-Polar Expedition, Plexechinus 
Nordenskidldi and Amphipneustes Koehleri from the Swedish South- 
Polar Expedition, Plexæechinus hirsutus, Pourtalesia Wandeli and 
Pourtalesia. paradoxa from the "Ingolf”-Expedition. 
Urechinus Drygalskii n. sp. 
Differs from CU. naresianus in the configuration of the posterior 
end of the test; the periproct is just above the ambitus, rather 
sunken, the test produced beyond it, both above and below. There 
is a distinct subanal-fasciole. Otherwise. it jagrees with U. naresianus 
in form and structure of the test. The globiferous pedicellariæ afford 
a very distinet character; the valves end in a single long tooth, 
whereas in U. naresianus there are|9 long slender, gracefully 
curved teeth, surrounding a terminal opening. 
"Near the Antarctic Continent; 3423 Meter: (German South- 
Polar Expedition.) 
Vidensk. Meddel. fra den naturh. Foren. 1905. 16 
