Ol'AIl. 



125 



rays at the l)egiiiMiii^ of tlie dorsal tin, the first is 

 extremely short, and uiiiUid to the l)as(! of the second, 

 which in the specimen Ix-loni^ing' to the Uoval Museum 

 is broken oft' short, hut according to Lowk is the 

 longest ray in the whoh; fin. A peculiai-, fidcilnrni, 

 interspinal hone, with lhe concave margin grooved, 

 lies loose in the flesh Ijetween the occiput and the 

 first dorsal tin''. The tii'st true interspinal bone is both 

 long and high, with tlu^ curved anterior margin dilated 

 and ^virh several pairs of hitei'al ridges, tiie posterioi', 

 in particular, liigh and shar[), but h'ss so than on the 

 eight next following interspinal bones. The intcrs])inal 

 bones are gradually reduced in length in the same 

 proportion as the length of the rays in the dorsal fin 

 from the first branched ray to the twelfth. The neural 

 spines in the alxlominal region, on the other hand, 

 become longer posteriorly. The dorsal fin in form 

 resembles that of the Swordtish: behind the elevated, 

 falciform, anterior |)art folKnvs a lo^w portion, from the 

 fourteenth ray to the seventeenth inclusive, in the spe- 

 cimen of the Itoyal Museum, and then tlie fin again 

 rises, though slo^vl}• and inconsiderably. The anal fin 

 throughout its length resembles the posterior part of 

 the dorsal. The lateral line is sharply curved in an 

 elevated arch anteriorly, and then runs straight along 

 the body in the middle line of the depth. 



The Opah is one of the deep-sea fishes of the 

 Atlantic, known from Norwegian Finmark, Iceland and 

 Newfoundland at least as far south as Teneritt'e, and 

 also occurs in the Mediterranean, but is genei'ally very 

 rare. In Madeira, however, according to Lowe, it is 

 fairly often brought to market during spring. It can- 

 not, however, be reckoned among the inhabitants of 

 the deepest regions, as seaweeds are occasionally found 

 with other food in its stomach. Its food consists chiefly 

 of cuttlefish, thin-shelled Isopods which have their home 

 in the alga?, Herrings and, probably, other small fishes. 

 It is caught ott" ^ladeira, says Lowk, with hooks l)aited 



with Mackerel or Scad, at a depth of from 50 to 100 

 fathoms. This depth, if indeed it be the Opah's pro- 

 per home, is great enough to prevent it from moving 

 freely at its pleasure at the surface", ^\■hcn for some 

 reason or othei' it suddenly rises into the higher re- 

 gions of tlie ocean. Thus, like other deep-sea fishes, 

 it is often found floating hcli)lessly at the surface or 

 cast ashore by the waves. It attains a length of aljout 

 4V2 feet (I'/a metres)''; but most of the specimens 

 known have measured between 3 and 4 ft. in length. 

 Its whole body is very fat, and its flavour is compared 

 by most of tliose who have tasted it, to that of the 

 Salmon; but Mr. Olsex writes to me that a part of 

 his Opah tasted like beef, another part like veal, a 

 third like brain, and a fourth like "fish." In Madeira, 

 says Lowe", the flesh of the Opah is considered better 

 and costs more than that of the Tunny. "Formerly, 

 I am informed, it Avas held in such esteem that every 

 fish taken was obliged by law to be carried to the 

 governor of the Island, without whose licence it could 

 not be sold in the market." 



In Norway the Opah is rai-e, but according to 

 both LiLLJEBORG and Collett a specimen is taken al- 

 most every year in the neighbourhood of Bergen. So 

 early a writer as Pedek Claussen-'^ knew it from Nord- 

 land and called it ''den skone Laxestorjc" (the beautiful 

 Great Salmon). It has been met with several times 

 in Christiania Fjord and, strangely enough, off the 

 coast of Zealand and near Helsingborg. It was from 

 the last place that Retzius described it for the first 

 time as a Swedish fish. We have fewer mentions of 

 it from Bohusliln; but according to Malm it is known 

 to a few of the fishermen by the name of ''makril- 

 storje". Ekstrom (1. c.) mentions a specimen which 

 was caught in the forties in the neighbourhood of 

 Stromstad; and the specimen of the Koyal Museum 

 which we have already mentioned, was taken at the 

 beginning of August, 1873, by some fishermen from 



" Cf. Lowe, 1. v.. p. 29. 



' Cf. Lowk. 1. c, p. .'U. 



"" See abovr, under Genus Ciirnnx. 



'' Baikik (ZooL 1853), according to Day (L c), nientiims a ppecimen 6 ft. long, wliicli was caught oil Sanda^". one of tlie Orkneys. 

 The specimen mentioned above which was examiiieii bv Oi.SEX. he states to liave measured 5 ft. iu lengtli, 3 ft. in depth and 10 in. in 

 thickness. 



' 1. c, p. 3.5. 



' .\orrif/es BcfcriffneUe, Kjobenhaffn 1032, p. 120. 



