1912.] NATURAL SCIENCES OF PHILADELPHIA. 389 



Polypus pusillus (Gould, 1852). 



Octopus pusillus Gould, 1852, p. 478, fig. 591. 

 Octopus pusillus Tryon, 1879, p. 112, pi. 31, figs. 31-33. 

 Octopus pusillus Ortmann, 1888, p. 644, pi. 21, fig. 1. 

 ? Polypus pusillus Hoyle, 1904, p. 16, pi. 4, fig. 5. 



The identity and important characters of this species are scarcely 

 yet established upon a firm basis, for it seems to me questionable 

 whether the Western Pacific specimens referred by Hoyle (1904) 

 to P. pusillus are really conspecific with Gould's type. The rela- 

 tively wide umbrella (one fourth as long as the arms) arm formula 

 1, 2, 3, 4, lack of cirri, smooth skin, and large, prominent eyes 

 appear to be the most salient features noted in Gould's de- 

 scription. 



Distribution. — Kagoshima, Satsuma (Ortmann). Mangsi Islands, 

 China Sea (type locality, Gould) ; off the southwest coast of Central 

 America (Hoyle). 



Polypus macropus (Risso, 1826). 



Octopus macropus Risso, 1826, vol. 4, p. 3 (fide Hoyle). 



Octopus Cuvierii d'Orbigny, in d'Orbigny and Ferussac, 1826, Poulpes, pi. 4 



{fide Hoyle). 

 Octopus Cuvieri Appellof, 1886, p. 6, pi. 1, fig. 6. 

 Octopus macropus Hoyle, 1886, pp. 11, 95. 



Octopus macropus Ortmann, 1888, p. 643, pi. 21, fig. 3 (hectocotylus). 

 Octopus macropus Joubin, 1897a, p. 99. 

 Polypus macropus Wi'ilker, 1910, p. 8. 



The loose, soft, elongate body; long, attenuate, and very unequal 

 arms; short umbrella; curiously formed hectocotylus, and nearly 

 smooth surface serve to distinguish P. macropus from any of its 

 Japanese congeners. The arms of the various pairs are conspicu- 

 ously different in proportion, their order persistently 1, 2, 3, 4, and 

 the dorsal pair much the stoutest and longest. The right third 

 arm of the cf is scarcely half as long as its mate of the opposite side 

 and terminates in an extremely conspicuous, oblong, trough-shaped 

 hectocotylus, ornamented with perhaps 8 or 9 prominent transverse 

 ridges on its inner surface and so thickened as to greatly exceed the 

 adjacent portion of the arm in diameter. 



The skin is in general smooth, but the present material shows 

 usually about three small conical tubercles just above and behind 

 each eye-opening, with a few scattered smaller ones occasionally 

 apparent over the rest of the dorsum. 



The more important measurements of two specimens are given 

 below, both being males: 



