378 GEOGRAPHICAL DISTRIBUTION. 



"intermediate" hauls with open nets of one sort or another, and of specimens 

 entangled on sounding or dredging wire. 



The only species which have never been taken in surface hauls are Chuni- 

 phyes multidentata, Nedopyramis diomedeae, Nedodroma reticulata, Erenna 

 richardi, Erenna bedoti, Dromalia alexandri, Angelopsis globosa, Angelopsis 

 dilata, Archangelopsis typica, and the various Bathyphysinae. 



Nedopyramis diomedeae and Nedodroma reticulata are known from so few 

 records that they may well have come from the surface, and it is altogether 

 probable that Dromalia, Archangelopsis, and Angelopsis did come from the 

 surface (p. 316). This leaves only Chuniphyes, Erenna, and the Bathj'physinae 

 belonging exclusively to the mesoplankton. The shallowest haul which has 

 produced a specimen of the former was 250-0 fathoms (Bigelow, : lib, p. 348); 

 and the records from closing-nets just cited show that it is at home at much 

 greater depths. We do not know the precise level from which any Bathyphysid 

 or Erenna has come. But all of them are so large and conspicuous that they 

 would hardly have been overlooked on the surface in the warmer parts of the 

 globe, did they occur there. And the surface waters off the coast of Norway, 

 about Spitzbergen (Romer) and in the Greenland Sea (Duke of Orleans) have 

 been so thoroughly examined within the last few years that we can hardly sup- 

 pose that any of them regularly come to the surface in these cold regions. 



The great majority of Siphonophores are epiplanktonic at some time or 

 place, many of them chiefly, or perhaps exclusively, so. Thus during the 

 expedition of the "Albatross" seventy specimens of Galeolaria australis were 

 taken in twenty-seven surface hauls, and only seven specimens in four inter- 

 mediate hauls. The preponderance in favor of the former is so great that it 

 strongly suggests a surface origin for the latter. Evidently this species was 

 living in a shallow surface zone. In the Malaysian region, also, all (but perhaps 

 one) of the "Siboga" specimens of G. australis were taken on the surface. As 

 further examples of the epiplankton group I may mention Sphaeronectes trun- 

 cata, Galeolaria monoica, G. quadrivalvis, and Diphyopsis dispar. 



Among Physophorae, Agalma okeni, Athorybia, and Anthophysa are char- 

 acteristic surface forms. During the Expedition seventy-eight colonies of the 

 former were taken on the surface, and only three in intermediate hauls. It is 

 common, likewise, on the surface at the Canaries, among the West Indies, near 

 Ceylon (Haeckel, '88b, "Cystallodes vitrea"), and among the Malaysian Archi- 

 pelago. And of course Velella, Porpema, Porpita, and Physalia, in the adult 

 state, are known from the surface only, though the larvae of the first and perhaps 

 of the others, are inhabitants of the deeper layers (p. 380). 



