. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. ECHINOIDEA. II. 67 spines. In these characters /'. miranda agrees with P. laguncula, and Agassiz ( Challenger -Echini p. 1371 is certainly right in stating that this species is closely allied t<. . Also the P. Tanneri is regarded by Agassiz as closely related to P. laguncula; it is, however, not clear from his otherwise (regarding the structure of the test) very elaborate description and figures of this species, whether it agrees with laguncula (and miranda) in the shape of the spines and the development of the
. The Danish Ingolf-Expedition. Scientific expeditions; Arctic Ocean. ECHINOIDEA. II. 67 spines. In these characters /'. miranda agrees with P. laguncula, and Agassiz ( Challenger -Echini p. 1371 is certainly right in stating that this species is closely allied t<. . Also the P. Tanneri is regarded by Agassiz as closely related to P. laguncula; it is, however, not clear from his otherwise (regarding the structure of the test) very elaborate description and figures of this species, whether it agrees with laguncula (and miranda) in the shape of the spines and the development of the front ten- tacles. Of the spines it is only said: the primary radioles on the flanks of the test are also longer, while in P. laguncula and P. miranda they are somewhat spathiform (Pan. Deep-Sea Kch. p. 132). The front tube-feet are not mentioned at all. Having received a specimen of /'. Tanneri from the Q. S. National Museum I can state that the spines are not widened towards the point, whereas the frontal tube-feet are really rather large and conspicuous The pedieellaria: do not afford any proof of a close relationship between P. Tanneri and laguncula. In the former species I have found only rostrate pedicellariae with rather slender valves (PI. XI. Fig. n) and small tridentate pedicellariae of the same form as in P. Jeffreysi. In P. laguncula (examined in the British Museum) I have found (in a specimen from St. 232) globiferous pedicellariae with the valves ending in two or three long teeth, resembling closelv those of P. carinata (comp. PI. XL Figs. 16, 22), ophicephalous pedicellariae with rather elongated, slender valves (PI. XI. Fig. 12) — (differing considerably from those figured in the Chall. -Ech. PI. XLIII. 18 — 19 under the name of < Clypeastroid-like pedicellariae, so much, indeed, that they can scarcelv be- long to the same species) — and two forms of tridentate pedicellariae, viz. the usual small form, which, however, here occurs also with the apophysis
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