. The Cephalopoda of the Hawaiian Islands. Cephalopoda; Mollusks. CEPHALOPODA OF THE HAWAIIAN ISLANDS. 283 into practically a single row on the distal portion of the dorsal arms, contemporaneous with the general atrophy of the arm itself. The suckers of these arms are ultramarginal except as just noted, and the rows very widely spaced; the suckers of the third arms are somewhat intermediate between this con- dition and that which prevails on the ventral pair. Male: Body much smaller, perhaps half as large as that of the female, but quite as variable in shape (figure 10 shows the extreme of rot
. The Cephalopoda of the Hawaiian Islands. Cephalopoda; Mollusks. CEPHALOPODA OF THE HAWAIIAN ISLANDS. 283 into practically a single row on the distal portion of the dorsal arms, contemporaneous with the general atrophy of the arm itself. The suckers of these arms are ultramarginal except as just noted, and the rows very widely spaced; the suckers of the third arms are somewhat intermediate between this con- dition and that which prevails on the ventral pair. Male: Body much smaller, perhaps half as large as that of the female, but quite as variable in shape (figure 10 shows the extreme of rotundityV Arms relatively shorter and more delicate than in the female; the four dorsal arms much less highly specialized, their tips normal, and the very delicate webbing not so well developed. Right ventro-lateral arm hectocotylized, the modifica- tion affecting the entire arm, which attains its development in a specialized sac occupying the region which w7ould ordinarily be the base of the arm between the base of the funnel and the eye. (Cf. the account given by Steenstrup, 1857, p. 103-105.) It is visible through the thin overly- ing integument even in very young specimens as a whitish vermiform body compactly coiled upon itself in such a fashion as to occupy as little space as possible. This arm undergoes a much more rapid growth than the rest of the animal, so that in males measuring about 3 cm. in length (station 4010) the sac is already vigor- ously crowding the eye and funnel and the ani- mal has consequently a somewhat lopsided ap- pearance ; at this stage also the sac has begun to bulge forth by the side of the mouth as a large rounded tumor-like protuberance. In the large mature male from station 40S6, the arm had apparently just broken from its sac, but still re- mained attached by its basal end at the time of capture. At this stage the hectocotylized arm is a highly complex structure as long or longer than the animal itself. It differs very markedly from the hectoco
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Keywords: ., bookcentury1900, bookdecade1910, bookpublish, booksubjectmollusks
