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Pleæxechinus hirsutus nm. sp. 
Closely related to the Pacific species, P, cinctus A. Ag., from 
which it is, however, easily distinguished by the shape of the test, 
the actinal keel being much larger and the anal snout much less 
prominent than in that species. The labrum is, generally, not 
separated from the second plate of the posterior interradium. Other- 
wise it agrees with P. cinctus in the structure of the test. Spines 
slender, very numerous. 
Northern Atlantic; Denmark Strait. c. 450—1300 fathoms. 
(fIngolf”-Expedition.) 
Pleæxæechinus Nordenskidldi n sp. 
Differs considerably from the two other species in several 
respects. The labrum is not separated from the second plate of 
the posterior interambulacrum. Four genital pores; all four genital 
plates distinct. Shape of the test as in P. cinctus. Only few, 
stout spines. 
Lat. 53” 34' S. Long. 43? 23' W. (Shag Rocks Bank) 160 Meter. 
(Swedish South-Polar Expedition.) 
Pourialesia Wandeli n. sp. 
This is a large species like P. Jeffreysi, from which it is 
easily distinguished by the shape of the test; it is somewhat more 
elongate and slender than in that species, and slopes gently towards 
the posterior end, not produced over the periproct. An abactinal 
keel may be slightly developed in younger specimens, in larger 
specimens there is almost n0 trace of such a keel. The structure of the 
test otherwise as in P. Jeffreysi. The primary abactinal spines of 
the antero-lateral ambulacra very long, curved and bent backwards 
over the test, reaching almost to the posterior end of it; they are 
rather coarsely thorny. Also the pedicellariæ show some minor 
differences from those of P. Jeffreysi. 
Northern Atlantic; Davis Strait. 845—1715 fathoms. (”Ingolf”- 
Expedition.) 
] 
ERE ETERN 
