INTRODUCTION. V 



has occurred five times. On the other hand, Chiasmodon, although so abundant, has only 

 ouce beeu taken by the deep-sea nets. 



Another ocean dweller which the exploring ships have not yet discovered is 

 Rcfjalecns, or the ''Oar-fisli," a serjient shaped, rapidly swimming form, usually from IS 

 to 24 feet in length, which occasionally is stranded on the shore in the stormy season. 

 Within the past one hundred and fifty years individuals have visited the shores of Nor- 

 way, Finmark, the Faroe Islands, Scotland, Ireland, England. ^leditenanean, France, 

 Bermuda, the Cape of Good Hope, Hindustan, and New Zealanil. (iiintlier gives a list 

 of 44 seen by naturalists, aud this is of course but an insignificant part of those which 

 have actually been stranded. Its worldwide distribution and the nundjcr of waifs give 

 evidence that it is abundant in mid-ocean, ye-t the exploring sliips in all the years of their 

 combined searchings have found no vestiges of it, old or young. 



jMany similar cases might be cited, but our object is siini)ly to call attention to the 

 great necessity for further exploration of the depths. 



The distinctions between the inhabitants of deep water, those of the middle depths, 

 and those of the surface strata of mid-ocean are not yet absolutely fixed. Such are the 

 imperfections in the methods of trawling and dredging that the naturalist, when he has 

 sorted out the fishes from his nets after a haul in mid ocean, is often in doubt as to where 

 his captures have been made. If he has takeu a tlounder from a haul of SOO fathoms, or 

 finds a macrurid, a brotulid, a stomiatid, a synodontid, or a nemichthyid in a net which 

 has been below the 2,(IO()-fathom line, he feels reasonably sure that he has biought it u|» 

 from the bottom. But who shall say where Argyyopclccus, Sfcnwptyr, Myctophuin, having 

 allies among the pelagic fishes in the same net, have come from"? It may be from the 

 bottom, or they may have become entangled in the meshes of the trawl when but a few 

 fathoms from the surface, coming up or going down. 



The receut investigations of Mr. Agassiz in the Pacific, with the Tanner net, seem to 

 show pretfy conclusively that there are but few living forms below a depth of 1,800 or 2,000 

 feet aud that the Mtictuphidw stay for the most part, if not entirely, between that depth and 

 the surface. It is possible to draw inferences from the experiments in regard to mauy forms 

 which, like the Mi/ctophida; are known frequently to occur swinnuing at the surface at 

 night, but there are also doubtful cases, like Bathyoi)his, RhodichthyK, Microstoma, aud many 

 others, which need further consideration. 



Another great need is for more, and miu'e perfect, nuiterial. Fully one-half of the deep- 

 sea forms are now represented only by single specimens, and many important anatomical 

 questions can not be solved, because these uniques may not be sacrificed to dissection. Half 

 of the families of Malacopterygians mentioned in this report can not be assigned to their 

 proper places, because their skeletons have not beeu fully examined. 



Besides this, tlu^ imperfection of the existing specimens is a great drawback. The 

 nuiterial is of a kind which it is peculiarly difiicult to study. Not only are the forms 

 strange and difficult to assign to their proper taxonomic relationships, but, owing to the 

 soft, cavernous skeletons, and the tlabby muscles, tender skins, deciduous scales, aud fragile 

 ap])endages which are characteristic of many of tiicm, they are very liable to injury. After 

 these delicate animals have been drawn up from a depth of 2 or 3 miles iu rough nets, they 

 are, as might be expected, iu a very dilapidated condition. It has often been found Tieces- 

 sary to exanune a score of more of individuals, in order to be able to api)reciate characters 

 which could commonly be made out from a single specimen. 



The studies which have led to the writing of this book were begun iu the summer of 

 1S77, wheu the first deep-sea fishes were caught by American nets on the coast of North 

 America. This took place in the Gulf of Maine, 44 miles east of Cape Ann, on the l!*th of 

 August, when from the side of the U. S. Fish Conunission steamer /Sjxml well the trawl net 

 was cast in IGO fathoms of water. The writers were both standing by the mouth of the net 

 when, as the seaman lifted the end of tlu; bag, two strange forms fell out on tlu' deck. .\ 

 single glance was enough to tell us that they were new to our fuuia, ami probably unknown 

 to science. They seemed like visitors from another world, and none of the strange forms 



