NA TURE 



145 



THURSDAY, DECEMBER 17, 1885 



THE NORWEGIAN NORTH ATLANTIC 



EXPEDITION— CRUSTACEA 



The Norwegian North Atlantic Expedition, 1876-78. 



Zoology. XIV. Crustacea, Ia. and Ib. By G. O. 



Sars. 4to, pp. 280, with 21 Plates and a Map. 



(Christiania, 1885 ; London: Sampson Low and Co.) 



NO better evidence can be adduced of the growing 

 influence exercised by the cultivation of natural 

 science than in the more ready tendency displayed by the 

 Governments of various countries to promote expeditions 

 for scientific purposes, and a greater willingness to furnish 

 the necessary means for the publication of the results in a 

 satisfactory manner. 



Nor can v/e fail to look back with a feeling of pride to 

 the work accomplished by our own early naturalists, from 

 the days of Banks and Solander (1768-77) to the voyage 

 of the Beagle (1844-46), which the "Journal" and 

 " Observations " of Charles Darwin have for ever ren- 

 dered famous ; and down to the recent magnificent 

 results of the Challe?iger Expedition, which its grand 

 publications are rapidly unfolding to us. 



The prospectus of the " Norwegian North Atlantic 

 Expedition" was announced in NATURE, June 2, 188 1 

 (p. 108), and the memoir on the Gephyrtea by Danielsson 

 and Koren was noticed September 29, 1S81 (p. 506). 



The present memoir by Prof. G. O. Sars, on the 

 Crustacea, occupies two quarto parts, illustrated by up- 

 wards of 600 figures drawn by the author himself from 

 the actual specimens by means of the camera lucida, 

 " thus affording a sufficient guarantee for their accuracy." 



One cannot fail to be struck by the results obtained by 

 the author in so comparatively limited an area, over part 

 of which, at least, other naturalists must have ahead)- 

 worked. The map embraces the ocean from the North 

 of Scotland to Spitzbergen, and from Norway to Iceland 

 and Greenland ; or from 55° to 80° north latitude, and 

 from 40° east to 25° west longitude. 



" To avoid repetition in stating localities," writes Prof. 

 Sars, " I have given a list of all the stations at which the 

 dredge or the trawl was used, along with the date, posi- 

 tion of the vessel, depth, bottom-temperature, nature of 

 the bottom, and character of the apparatus. With but 

 very few exceptions crustaceans were obtained at all these 

 stations. Moreover, pelagic forms were collected with 

 the surface-net at many other stations not included in the 

 list. At the coast stations enumerated in conclusion, a 

 smaller dredge was made use of, either from a boat, or 

 from the ship when lying at anchor. 



" The stations enumerated in the list have all been 

 accurately set off on the map in which the curves of depth 

 for 500, 1000, 1500, and 2000 fathoms are drawn as dotted 

 lines. In the map will also be found a more strongly- 

 marked curve, indicating the boundary-line between the 

 cold and temperate areas, determined from the observed 

 bottom-temperatures. This curve also forms the natural 

 limit of the ocean valley — reaching 2000 fathoms in 

 depth, and " filled at the bottom with ice-cold water — 

 which shelves from the Polar Sea to the tract between 

 Norway and Iceland, and, in the form of a narrow wedge, 

 terminates in the so-called ' Faeroe-Shetland Channel,' 

 where it is cut off by a narrow transverse ridge from the 

 great depths of the Atlantic" (p. 2). 

 Vol. xxxiii.— No. 842 



Of the list of results of work performed at the eighty-six 

 stations, either by means of the dredge, the trawl, or 

 with " swabs," sixty give a bottom temperature of from 

 0° C. to 2° C. only ; the highest reading being 7° C., in 

 237 fathoms close to the coast of Norway ; whilst the 

 average temperature at the bottom is only 2°-3 C, or 

 3° above freezing-point. 



The deepest dredging recorded in Sars' list is 1861 

 fathoms, with a bottom-temperature of l°'2 C. ; but at 

 p. 159 he mentions that Harpinia abyssi was obtained 

 from a depth of 2215 fathoms. 



In treating of the crustacean fauna of this region Pro'f 

 Sars has not included forms previously established as 

 belonging to the Norwegian littoral fauna. Such forms 

 will be fully treated of elsewhere, in a work on the 

 Crustacea of Norway, to be shortly executed by the 

 author. 



Some idea may be formed of the extreme Arctic facies 

 presented by the Crustacea inhabiting the depths of this 

 cold-water area of the North Atlantic by noticing the 

 relative proportions of species appertaining to each order 

 recorded by Sars. 



Thus of the Brachvura i species only is recorded 

 (Scyramathia Carpenteri, Norman) from 220 fathoms ; 

 a form described and figured in Sir Wyville Thom- 

 son's "Depths of the Sea" (p. 175). From the 

 slight development of the eyes and their light-coloured 

 pigment it was probably blind, as is the case commonly 

 with the Crustacea from great depths. 



Of the AnomoURA only I species {Eupa^urus tricari- 

 nattis, Norman) was taken in about 98 fathoms. 



Four species of Caridea are described, the largest of 

 these, Sclerocrangon salebrosiis (Owen), appears to be 

 widely distributed in the northern seas, ranging from 100 

 to 459 fathoms ; but off the coast of Kamschatka, ac- 

 cording to Tilesius, it is found abundantly in shallower 

 water, and serves as an article of food to the natives. It 

 ranges from Norway to Spitzbergen (p. 25). 



Of the two species ol Bythocaris, B. leucopis G. O. Sars, 

 and B. Payeri, Heller, it is interesting to notice that the 

 young of this Caridian do not pass through the usual 

 post-embryonic metamorphosis, or larval stage, but on 

 quitting the remarkably large ova, they are seen to be 

 provided with the full number of appendages observed in 

 the parent. All the species are true deep sea forms 

 (mo fathoms!), the eyes being unusually small and 

 imperfect. 



The next form, Hyinenodora glacialis, has legs, as in 

 the Schizopods, with a well-developed natatory branch 

 (exopodite) attached to the outer side of the second joint. 

 The eyes are small and imperfectly developed. It would 

 seem to lead a semi-pelagic life, but it was taken at a depth 

 varying from 452 to 1862 fathoms in the cold area. 



Of the Schizopoda five species of " opossum shrimps," 

 Mysidir, were taken : Erythrops gracilis in from 263 to 

 49S fathoms, and Pseudomysis abyssi, Sars, from 1 1 10 to 

 1280 fathoms ! Boreomysis tiobilis, 6 mm. long, was taken 

 off the north-west coast of Spitzbergen, 80° N. lat. in 450 

 fathoms. The most remarkable of these deep-sea My- 

 sidce is the Boreomysis scyphops. " The eyes in this spe- 

 cies are remarkable alike in character and form, their 

 outer surface being, instead of convex, considerably 

 hollowed, which gives them a well-nigh calyciform 



