CEPHALOPODA OF THE HAWAIIAN ISLANDS 277 



to suffer a certain reduction when better methods, better appliances, and more extensive researches 

 have further enriched our museums, but for the present there seems no way of dealing with them 

 except to carefully describe each apparently divergent specimen as it comes in. 



The dimensions attained by L. lugubris should often be considerable, as when living the larger of 

 the specimens in hand must have had a total arm spread of over 80 centimeters. 



Although neither of the Hawaiian specimens was actually obtained from an abyssal depth, there is 

 every reason to believe that such was in reality their place of origin. 



Family ARGO\AUTID£ (Cantraine 1840) Gray 1847. 



A rgonautides Cantraine 1S40. p. 30. 



Philonexidaz d'Orbigny 1S45, p. 199. 



Ocythoina Gray 1847, p. 204. 



Ocythoidae ( Argonautida: ?) Gray 1849, p. 3, 28. -f Philonexidce Gray, op. cit., p. 3, 29. 



Argonaulidce H. and A. Adams 1853, vol. x, p. 23. 



Argonaulidce (pars) Nad 1912b, p. 197, 198. 



Octopods of small to moderate size and pelagic habit. Body rounded or slightly elongate ; without 

 fins. Sexes conspicuously dimorphic. Males much smaller than the females; hectocotylization affect- 

 ing one of the ventro-lateral arms, which, having its origin in a specialized sac, becomes developed into 

 a highly modified and detachable copulatory organ, which persists separately for a certain length of 

 time in the mantle cavity of the female. Suckers in two rows on all the arms. 



Subfamily ARGONAUTIN^) s. s. 



Third right arm of male hectocotylized ; outer aspect of hectocotylus smooth. Dorsal arms of 

 female furnished with broadly expanded glandular membranes at their extremities, which serve to 

 secrete and hold in embrace a delicate involute calcareous shell, which latter functions as an ovarium 

 as well as a partial retreat for the animal itself. Articulation between mantle and funnel cartilaginous. 

 Funnel organ comprising a /\ -shaped dorsal cushion and a pair of ventro-lateral pads. 



Genus ARGONAUTA Linne 1758. 



Argonauta Linne 1758, p. 708. 



Nautilus Schneider 1784, p. 120 (not of Linne 1 17S8). 



Ocylhoe Leach 1817, p. 295 (not of Rafinesque 1814). 



Hectocotylus (pars) Cuvier 1829, p. 147. 



Todarus Rafinesque 1840, p. 64 {fide Binney and Tryon, p. 94). 



Argonauta d'Orbigny 1845, p. 210. 



For the characters of this genus see above under the subfamily, of which this is the only known 

 group. Here are included the familiar argonauts or "paper nautili." At least two species are inhabi- 

 tants of the Hawaiian region . 



Type. — Argonauta Argo Linne 1758 (the species first mentioned), a characteristic Mediterranean 

 type. 



Argonauta bottgeri Maltzan 1881. (PI. xlviii, fig. 5.) 



Argonauta Bottgeri Maltzan 1881, p. 163, pi. 9, fig. 7. 

 Argimaula bottgeri Smith 1887, p. 409, pi. 17. fig. 1-6. 

 Argonauta Bottgeri Hidalgo 1905, p. 9 (fide Hoylc 1909). 

 Argonauta bcetlgeri Dall 190S, p. 226, 2:9. 

 Argonauta bottgeri Berry 1909, p. 418 (locality record only). 



Animal small, pelagic. Male (with the exception noted below) unknown. Body of female smooth, 

 elongate, in general cylindrical, twice as long as broad; posterior part of body with a sharp upward 

 torsion, at least in animals preserved in situ within the shell; rounded below, elevated and bluntly 

 pointed posteriorly, widest in front, much elevated just back of the nuchal region. Mantle margin thin; 

 pallial opening very wide, reaching well above the eyes on either side. 



