cephalopoda of The Hawaiian islands. 
279 
Fig. 5 . — Argonaula bdttgeri, out- 
line drawing of funnel laid 
open medioventrally to show 
the funnel organ [165], X 2. 
modified extremities of the dorsal pair, on which latter only the basal 15 to 16 are at all well developed. 
The funnel is connected to the head dorso-laterally by a pair of delicate bridle-like connective mem- 
branes, which are continuous with a delicate keel running along tire lower aspect of each ventral arm ; 
otherwise the arms are rounded and devoid of keels or swimming membranes. Dorso-laterally the 
integument of the head is connected with the dorsal arms by a delicate 
vertical membrane bridging the sulcus which otherwise separates the arms 
and head, and two similar but smaller membranes bridge the constriction 
between the anterior boundary of the eyeball and the lateral arms. 
Shell small for the genus, coiled very compactly in an even plane, 
laterally compressed; the sides ornamented with some 30 or more conspicu- 
ous ridges radiating from the shallow depression which is tire outward 
mark of the shell axis; periphery flattened, each angle decorated with a 
row of bluntly squared tubercles, 17 to 18 of which can be made out on 
each side; margin of aperture simple, without any trace of lateral expan- 
sions or “auricles;” surface finely and quite evenly granulose, tlie granules 
most numerous on either side of the shell near the axis and visible wdthout 
the aid of a lens (fig. 4) . 
General surface color of animal in alcohol everywhere a pale brown- 
ish buff, dotted more or less impartially with numerous fairly large bluish black chromatophores, 
which are nowhere crowded save on the outer aspect of the dorsal 
arms and in less degree the dorsal integument of the eyeball. 
Beak coal black. 
As no male animal of this species has come to hand the above 
description applies only to the female. However, the mantle of 
the specimen before me was carefully laid open along the medio- 
ventral line; lying within the cavity, its thickened basal portion 
lodged snugly just above the left gill between the latter organ 
and the viscera, was found the detached hectocotylus of a male. 
This condition is well shown in the accompanying sketch, which 
indicates the position of the structures in question in situ (text 
fig. 6); see also the more detailed representation of the hecto- 
cotylus in figure 7. The organ comprises a thickened basal por- 
tion curved in the shape of a horseshoe about 6 mm. in length by 
a little more tlian 4 in breadth, with the inner or sucker bear- 
ing aspect outermost; widest between the middle and the base, 
tapering slightly to a rounded point posteriorly, and more gradu- 
ally to the acute distal extremity which terminates in a very long 
and slender thread-like process, lying in a loose coil; the basal 
portion broadly flattened on its inner surface, the margin of the 
latter armed with a closely placed row of minute much elevated 
suckers, about 22 on each border, which are connected by a deli- 
cate hyaline membrane; the outer aspect (i. e., inner curve of 
the horseshoe) is keeled and bears a conspicuous marginal mem- 
brane, which even continues along the terminal thread, though 
there becoming extremely thin and delicate. The diameter of the basal portion is 2 mm.; the length 
of the flagellum about 13 mm. 
The shell of this specimen was partly full of eggs and yoimg embryos connected into a loose mass 
by fine filaments and representing various early stages of development. The total number is several 
hundred at least, the largest scarcely a millimeter in length. 
Fig. 6 . — Argonauta bdttgeri [165], ventral 
aspect of female, with mantle laid par- 
tially open to show the detached hecto- 
cotylus of the male in situ within the 
pallial chamber, X 2: br., gill; hect., hec- 
tocotylus of male; I. app., locking carti- 
lages of left side; mb., thickened band 
of muscular tissue bordering mantle mar- 
gin; ov., gonad; sept., median septum of 
pallial chamber. 
