476 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



monsti'i's of the sea are always represented by those who have had tlie good fortune of 

 meeting with them as remarkably active, it is not likely that liarndess ribbon tishes, which 

 are either dying or dead, have been the objects described as 'sea serj)ents.'" 



KEY TO THE FAMILIES. 



I. Ventrals well developed or iibseut Trachypterip.e 



II. Ventrals reduced to a single long tilameut Regalecid.e 



Family TRACH YPTERID>E. 



Trar7u/p<m(in', SwAiNsoN. Nat. Hist. Fish.. 1839, 47.— Gill, American Naturalist, xxiv, 1890, 482. 



Ta'niosdmes with the body moderately elongated and very comjiressed, the head short, 

 tlie opercnlar apparatus abbreviated (the operculum extended downwards, the suboper- 

 culum below it, and the interoperciilum contracted backwards and bounded behind by the 

 ojierculum and snboperculum), ventrals ])aueiradiate in young, atro])hied or lost in adult, 

 the cranium with a myodome and dichost, the supraoecipital continiu'd behind into a ])romi- 

 nence, the epiotics confined to the sides and back of the cranium, and without ribs. 



The riblion-fishes are well known in the Eastern Atlantic and the Mediterranean, and 

 have even been found as far west as JNIadeira. Trachyptvrus has never been found in the 

 Western Atlantic. Some few representatives have been found on the west coast of South 

 America, and one or two exam]iles have been taken in New Zealand. They are generally 

 admitted to be true deep-sea tishes, which live at very great depths, and are only found 

 M'hen floating dead on the surface or washed ashore by the waves. Almost nothing is known 

 of their luibits except tlirougli Nilsson's observations in the far north. This naturalist, as 

 well as Olaisen, appears to have had the opportunity of observing them in life. They say 

 that tliey approach the shore at flood tide on sandy shelving bottoms, and are often left by 

 the retreating waves. Nilsson's opinion is that their habits resemble those of the ''flat- 

 fishes," and that they move with one side turned obliipiely ui)ward, the other toward the 

 ground; and he says that they have been seen on the bottom in 2 or 3 fathoms of water, 

 where the fishermen hook them uj) with the implements enijiloyed to raise dead seals, and 

 that they are slow swimmers. This is not necessarily the case, however, for the removal 

 of pressure and the rough treatment by which they were probably washed upon the shore 

 would be demoralizing, to say the least. Trichiiirvx leptxriis, a fish very similar in form, 

 is a very strong, swift swimmer. 



Whether or not the habits of Truchyptcrvs arcticus, on which these observations were 

 made, are a safe guide in regard to the other forms is a matter of some doubt, but it is 

 certain that they live far from the surface, except near the Arctic Circle, and that they 

 oidy come ashore accidentally. They have never been taken by the deep-sea dredge or 

 trawl-net, and indeed perfect specimens are very rare, the bodies being verj- soft and brit- 

 tle, the bones and fin rays exceedingly fragile. 



A considerable number of species have been described, but these are, in most instances, 

 based upon one or two specimens. It is probable that futuie studies may be as fruitful as 

 that of Enieiy, who, by means of a series of 23 specimens, succeeded in uniting at least 

 three of the Mediterranean species, which for half a century or more had Tieen regarded as 

 distinct. As has been remarked, not a single individual of Trachi/ptenix has ever been 

 found in the Western Atlantic, although the common species of the Eastern Atlantic, T. 

 alhtnlU-tix, is not unnsmilly taken, one or more specimens, according to Giinther, being 

 secured along the coast of Northern Euroi)e after almost every .severe gale. We have 

 deemed it desirable to include in this paper partial diagnoses and references to the litera- 

 ture coiieerning each of the s])ecies at i)resent recognized in the Atlantic Basin, in order 

 that American naturalists may have at hand a convenient means of identifying material 

 which is almost certain, sooner or later, to fall into their hands. 



We desire to <]Uote the recommendation of Dr. Giinther, and to strongly urge niiou 

 anyone who nuiy be so fortunate as to secure one of these fishes that no attempt should 



