4;^o 



SCANDINAVIAN FISHES. 



jaw ;ive also covereil with scales, l^ut the iiiterinaxillary 

 bones, as Avell as the lips, are naked. These small 

 scales on the head and fins are often the only ones 

 that are left after the fish is caught; but the scales of 

 tlie lateral line are at least nioi-e firmly attached than 

 the scales of the rest of the body itself. As a rule, 

 liowever, the dermal folds in which tlie st-ales liave 

 l>een set, are so distinct that the immber of the scales 

 may be ascertained. In the Scandinavian form ^\e have 

 found the number of scales in an oblique, transverse 

 vow at the beginning of the straight part of the lateral 

 line, just behind the arch (where the body is deepest), 

 to lie 13 above and 13 below the lateral line. 



In the form k^o^vn as Fl(doi)hrys coiispersus the 

 length of the head measures 19 — 22^/,, %" of the total 

 length of the body, 23—27 %'' of the length from tlie 

 snout to the base of the caudal fin, or 56 — 66 %' of 

 the greatest depth of the body. The snout is com- 

 paratively blunt, its upper and lower profiles meeting 

 almost at a right angle; and the mouth, with tiie lower 

 uiaigin of the under jaw straight, rises, when closed, 

 at an ano-le of about 45 degrees. The length of the 

 lo\\er jaw, which is some^vhat less on the eve side 

 tlian on the blind side, and in most cases relatively 

 less in old specimens than in young, measures 10 — 12 % 

 of the length of the body''. The chin is furnished 

 with a distinct, though small knob; and the anterioi- 

 margin (symi)hysis) of the lo\ver ja^v is straight and 

 together with the lower margin forms an obtuse angle. 

 The dorsal contour of the snout seems somewhat tumid 

 behind the intermaxillary bones, but farther back is 

 depressed. Tiiis is due to the comparatively advanced 

 development of the articular pai-t of the maxillary bones, 

 which in other species of the genus, e. g. in Fkttophnjs 

 hinatus from the tropical part of the Atlantic, sends 

 out a robust, spinous, bony knol) in a forward direc- 

 tion. In 1)i>th forms of /'/. Jdfcniii we have found the 

 Icngtii of the maxillarv bones to hv exactly the same 

 on the eye side as on tlie blind side'', and to measure, 

 ill the form known as /'/. loufpersH!^, 7 — 9 % of the 



length of the l)od_y', being relatively greater in young 

 specimens than in old. Behind (underneatli) the max- 

 illary bone is slightly extended in lireadth, and at the 

 posterior (lower) end obliquely truncate and slightly 

 concave, more so on the eye side than on the blind 

 side. The eyes are of moderate size, measuring 18 to 

 20 % of the length of tiie head, and are, as usual, 

 relatively larger in young specimens than in old. Their 

 position with regard to each other seems also to vary, 

 the variation being to a certain extent individual, Imt 

 chiefly according to age. In the young specimens be- 

 fore us they are set almost in a straight line with each 

 other, while in the oldest specimen lialf the upper e3-e 

 is behind the lower, the distance between the latter 

 and the tip of the snout being somewhat more than 

 its own length. The nasal cavity of the eye side is 

 naked, l)ut surrounded w\i\\ small scales, and is situated 

 in front of the eyes, almost exactly in a straight line 

 with the narrow interorliital ridge. The position of 

 the nasal cavity of the lilind side is similar, lint higher, 

 its longitudinal diameter, when produced, passing through 

 tlie middle of the ujiper eye, which is visible through 

 the bodv on this side. The anterior nostril is raised 

 on both sides of the body into an obliquely-truncate 

 tube, or elongated at the hind margin in a lobate sliape. 

 The posterior nostril is smaller, and only slightly raised 

 at the margin. The interorbital space, which in other 

 species of the genus I'latopJui/s is remarkable for its 

 great width and distinct concavit)', here consists of an 

 extremely narro\v ridge, the \\idth of \\hicli is only 

 about "o of the longitudinal diameter of the eye. In 

 old specimens the preoperculum is nearly rectangular, 

 but rounded at the corner, and with the upper, vertical 

 branch ' g or V* longer than the louver, horizontal 

 branch: in young specimens it is more obtuse-angled, 

 aiid the two branches are more equal in size. The 

 operculum, suboperculum, and interoperculum, are thin 

 and transparent, and together form an arch of almost 

 uniform width, until the last of the three grows nar- 

 rower in front, below the preoperculum. At the hind 



" In Scandinavian specimens at most 21' ^ '». in (me of our two Meiliterranean specimens 22'/o %. In our specimen of PI. arno 

 l/lossiis 24"7 "o. 



'' In Scandinavian specimens at most 26 %; in one of oiir two Mediterranean specimens 27'5 "■>. In our specimen of PL ariioglossus 29'2 "». 



'' In the smallest of Collett's specimens, however, this proportion is 08 "o. In the Royal Museum specimen of PI. aniofflossus it is 88'9 ",. 



■' In the Uoyul Museum specimen of PL arnoijlossiia the length of the branch of the lower jaw on the blind side is 14'1 "<. of the 

 length of the body. 



' The asymmetry of the mouth and the greater shortness of the head, especially of the postorbital part, and of the pectoral fins are 

 the only perceptible differences we Iimvc succeeded in discovering between the Cliineso Platopliri/s tapeinosoma and Platophrys conspersus. 



■' In our specimen of I'lnto/ihri/.-- arnoi/lossn.'i the length of the maxillary liones is lO'/o "o of that of the body. 



