Boone, Mollusca, Cruises of "Ara" and "Alva" 349 



slightly less conspicuous development of suckers, with three to 

 four alternating suckers of the dorsal series moderately enlarged. 



The tentacular arms are very elastic, slender, long, laterally 

 compressed, keeled near the distal end, with the inner surface 

 flattened; the club is expanded but little, recurved and with the 

 tip coiled upon itself; the inner surface appears villous, due to 

 closely packed series of numerous minute suckers. The separate 

 suckers are slightly oblique, deeply urceolate, with the papillary 

 area quite wide and the inner aperture decidedly reduced. The 

 pedicels are quite long, proximally columnar and closely crowded, 

 so that the suckers are mobile because of a shorter constricted 

 peduncle, about one-fifth as long as the proximal stalk and less 

 than one-fourth as wide, which unites the stalk and cupules. 



The buccal membrane is produced into seven points and is 

 thickened, with the margins plaited. 



There is no pen in this species. 

 The chromatophores make a very distinctive pattern of large, 

 transversely elongate chromatophores in close series along the 

 outer aspect of each sessile arm and a similar series of small chro- 

 matophores along the distal outer portion of the tentacular arms ; 

 the dorsal and ventral surfaces of the mantle are maculated with 

 numerous brownish dots. 



References: Euprymna scolopes, Berry, S. S., Proc. U. S. Nat. 

 Mus., 1913, vol. XLV, p. 564; Bull. U. S. Bur. Fish, for 1912 

 (issued 1914), vol. XXXII, Doc. 789, p. 312, pi. 49, figs. 5-8, 

 text figs. 23-26. 



Order: OCTOPODA 



Suborder: Incirrata 



Family: OCTOPODINAE 



Subfamily: Octopodinae 



Genus: OCTOPUS Lamarck 



Subgenus: Octopus d'Orbigny 



Octopus (Octopus) rugosus (Bose) 



y 



Plate 147 



Type : Bosc's type is not traceable. 



Distribution: Usually shallow water, there being only one 

 or two deep water records. The authentic records of the distribu- 



