FLOUNDERS OF GENUS PARALICHTHTS AND RELATED GENERA 



293 



Subgenus Lioglossina 



Lmlonxitw GillxMl. Pr.i.-. r. S. Nat. Mns. 13: 122, 1891 

 (Kfiiot.vpt' lHiiii()<jU)sxhiii iiliiJiilitlKihiius (Gilbert I = 

 Liii!ll»>"<i>ui UtrophthalmuH Gilbert by original desig- 

 nati(iti). 



This s(il)<ipniis diflFers ptructuriilly but sliirlitly 

 from Hipi'oglu.s'iiiui. The most striking diUer- 

 ence is in the size of the eye which is notably lar-ie 

 in the species of the stibgenus WippogloHHina iiiid 

 not so larpe in the two species here phiced in the 

 subgenns LlogJossina. Combined with this differ- 

 ence is the somewhat more anterior position of the 

 dorsal origin with resjiect to the anterior margin 

 of the eye in medium-sized and large specimens of 

 Lioglossina, and the weakly developed preunal 

 spine which does not i)roject exteriorly. Still 

 another difference is found in the number of scales 

 which is greater in the two known species of 

 Livjossina; but since the number of available 

 specimens in most species of these two subgenera 

 is limited, the value of this character is uncertain. 

 Quite probably, counts of more specimens will 

 show a certain degree of intergradation. Other 

 differences are given in the key. Wliile these 

 differences are hardly sufficient for subgeneric 

 division, the species of IlippogJossina have a 

 markedly distinctive physiognomy, due chiefly to 

 their strikingly large eye and the 6 conspicuous 

 spots. A consideration of all the characters 

 makes it seem desirable to maintain Lioglossina 

 as a subgenus distinct from Ilippoglossbm. 



LiogJossinty was originally based on, and dis- 

 tinguished from 11/ppogIos.sina by its cycloid 

 scales. This seems adequate as far as the geno- 

 type, tetrophthalmus. is concerned. However, 

 ohlonga, which is obviously most nearly related 

 to tetrofhthdlmus (p. 297), always has at least 

 some ctenoid scales. Their number in that species 

 is subject to great individual variability and some 

 specimens have very few ctenoid scales (p. 294). 

 It would seem to do violence to a natural arrange- 

 ment of the species to place ohloiuja and tctro- 

 phtholmus in separate subgenera. The presence 

 or absence of ctenoid scales in this subgenus is, 

 therefore, regarded as of specific imjOTrtance only, 

 although in FiiruVichthyH where this character 

 clearly distinguishes two groups of related spe- 

 cies, it is used for siibgeiiei-ir di\ision. The two 

 known species are Aiiiericaii. 



HIPPOGLOSSINA OBLONGA 

 Fourspotted flounder 



(PLATE 3) 



Common name. — The four prominent spots on 

 the eyed side of this species, usually surrounded 

 by a ring of lighter color, suggests an appropriate 

 common name for it, as given above. Tliis name 

 is generally emjiloyed in accounts of the species, 

 and is here adojjted. This common name con- 

 flicts with that of another species, Ancydop-setta 

 qiutdrocellaia. which occurs in shallow water on 

 the coast of the southern States. In order to dis- 

 tinguish the shallow water species, the name 

 "fourspotted shoal flounder" is suggested for the 

 latter fish, and since the present species is the more 

 important one from an economic point of view, 

 the shorter name is adopted for it. 



Diagn-osis. — At least a few ctenoid scales pres- 

 ent on blind side of caudal peduncle in fish be- 

 tween 60 and 75 mm. or longer; ctenoid scales 

 present on eyed side of head in large specimens, 

 usually present also on posterior part of body on 

 both sides; the niunber of spinuliferous scales 

 highly variable; scales 63 to 81. No accessory 

 scales. Gill rakers on lower limb of first arch 

 rallier short and stumpy, usually 8 or 9 in num- 

 ber, sometimes 7 or 10; on upper limb usually 2 

 gill rakers at angle somewhat similar to those of 

 lower limb, and 3 to 5, usually 4, tuberosities 

 above; tuberosities rarely becoming somewhat 

 elongate, resembling short chunky gill rakers: 

 sometimes the uppermost one of the two gill rakers 

 at the angle shortened resembling the tuberosities; 

 total number of gill rakers, not including the 

 tuberosities, usually 10 or 11, sometimes 9. infre- 

 quently 12 or 13. (The structure and number of 

 gill rakers, as described, is the same in the smallest 

 specimens examined, 44 mm.; the tuberosities, 

 tlierefore, not representing the stumps of gill 

 i-akers of young fish, but being the normal condi- 

 tion in this species, probably representing a rem- 

 nant of a more remote phylogenetic condition.) 

 Anal rays 58 to 72 ; dorsal'rays 72 to 86. Pectoral 

 rays usually 11, frequently 12, sometimes 10 (11 

 on both sides in 5 specimens, 12 on both sides in 

 3. 10 on blind side and 11 on the other in 1. 11 on 

 1)1 ind side, and 12 on the otlier in 3). Origin of 

 dorsal usually over anterior margin of pupil in 

 small fish, generally over space between anterior 

 margin of eye and that of pupil in medium-sized 

 and large specimens. Teetli sitbe(iiial in small fish. 



