40K 



SCANDINAVIAN FISHES. 



we further eoiiip.ire tliis table with tlie table given 

 nbu^ (■ (|). 401) (if tlie changes of growth in the Plaice 

 and the Flounder, we easily find that, in all those re- 

 lations in whicii the changes of growth of these two 

 species show a distinct and common direction of de- 

 \elopment, tlie ju\enile stages are represented either 



by I'l. VniKuida, I'l. f/lac/alis or PI. cicatricosns, or by 

 two of these forms in common. This series of forms, 

 which, as far as we kno^v nt present, culminates in the 

 Plaice and the Floimder, tluis seems to have originally 

 started either from one of these three forms or in close 

 systematic proximity to them. 



SuBFAJiii Y H I P P O L S S I N A. 



Snout iiiif cloi/f/dfcd, tlie loircr jair most prominent. Mouth middle-sized or laiije atid oiilij sligltthj oblique: Jair- 



teetJi (iliuost (IS irelJ-developed on the eije side (is on the hlind side. Yeiitrid fins one on eaeh side of the ventral 



inorf/in. and their rai/s close tor/etJier at the Inise. Eyes larf/e or at least middle-sized. 



]'sciidot)y(inehi(e and. in most eases, i/ill-rakers irell-devcloped. 



This subfamily derives its name from the well- 

 kiioAvn Halibut, Hippoglossus, and contains about 30 

 described species, distributed among .5 or, if we please, 

 .MS many as 9, distinct genera: {I'scttodes + Athe- 

 restes), {TUppoglossus + Platysomatiehthiis), {Paralielithj/s 

 + PseadorIiombiis). (I)repanopsetta + Psettichthijs) and 

 Tephyitis. The most mnnerous and the largest species 

 live in the North, but several belong to the tropical 

 seas, to West Indian, East Indian, Chinese and Ja|)a- 

 iiese waters. 



The ])eculiarity ^vhich we have remarked above as 

 characteristic of the ju\enile stages of the true Floun- 

 ders (subg. Platessa, auctt.), the pointed jaw-teeth set 

 in several rows, in this subfamily as \vell as in the 

 following one, is the rule even in adult specimens. 

 The |)rincipal characteristic of these two subfamilies 

 lies, h()^ve^•er, in the fact that the as^■nlmetrv of the 

 head has only slightly affected the sti'ucture of the 

 jaws. Thus, the jaw-teeth of the eye side niav be al- 

 most or even ([uite as \\ell-developed as those of the 

 blind side. On the (jther hand, the subfaniilv of the 

 Halibuts comes nearer the preceding Flattishes in the 

 position of the ventral tins and the form of the pelvic 

 bones. In essential res])ects at least, the ventral fins are 

 symnietrical in jiosition, one on each side of the ventral 

 margin; and the ])elvic bones are of the normal Hetero- 

 somatous ibrui, a narnnv triangle, and hang, closely 

 united to each otliei', backwards and downwai'ds or 



straight downwards (ventrallv) from the inner side of 

 the coalescent clavicular bones, Ijeing suspended within 

 and somewhat above the loAver end of the cpracoid 

 bones. To the outer side of the short base of the 

 triangle are attached, as usual, the rays of the ventral 

 fins, with their roots (articulations) close to each other. 

 Anothei' character that seems to be common to the 

 members of this subfamily lies in the circumstance that 

 all the caudal vertebrse are entirely without transverse 

 processes or possess onlv very slight traces thereof. 



The Scandinavian fauna contains only two, or, if 

 we choose, three, genera of this subfamilv. each genus, 

 in the latter case, with only one species. 



A: Jaw-tcctli, in the upper 

 jaw at least, set in two or 

 more rows. Scales cycloid. 

 a : Lower pharyngeal teeth 



set in two rows. Lateral 



line sharply arcuate in 



front, ahove the pec- 

 toral fins /Ji.jijioolossut< luihnii'is- 



li: Lower ]iharyngeal teeth 



set in a single row. 



Lateral line evenly 



slo]:)ing in front Platyt<uinatichtlojs hippoalossoides. 



B: -law-teetli set in a single 

 row". Scales ctenoid. 

 Lower pharyngeal teeth 

 set in two irregular rows. 

 Lateral line evenly sloping ] h-cpuiiopttettn plate.ssoides. 



" Does not apply In all exotic species of llie gciuis. 



