FAMILY, III— PLEUEONECTID^. 423 



Gill-memhranes united heneath the throat h%i,t not attached to the isthmus, GUI-rakers lanceolate. Eyes on the left 

 side without a free orbital edge : interorhital space not concave. Jaius and dentition nearly equally developed on loth 

 sides : teeth in both jaivs of unequal sizes and in a single row : vomer, palate, and tongue edentulous. Fin rays 

 simple, the dorsal commences on the snout, its rays, and those of the anal, are simple. Scales of moderate size, or 

 rather small, and extended on to the dorsal and anal fins. Lateral-line having a strong curve anteriorly. 



Geographical distribution. — East coast of Africa, seas of India to the Malay Archipelago, also to 

 the Pacific coasts of central and south America. 



SYNOPSIS OF SPECIES. 



1. Pseudorhombus arsius, D. 71-79, A. 54-61, L. 1. 75-85. From five to ten pointed teeth in either jaw. 

 Two dark blotches on the straight portion of the lateral-Line. East coast of Africa, through seas of India to the 

 Malay Archipelago and Australia. 



2. Pseudorhomhus Jacavicus, D. 69, A. 52-5.3, L. 1. 70-75. From 20 to 30 teeth in either jaw. Three 

 dark blotches along the straight portion of the lateral-line. Madras to the Malay Archipelago. 



3. Pseudorhombus trioceUatus, D. 69, A. 51, L. 1. 65-70. Teeth minute. Three heart-shaped purpli.sh 

 blotches placed in the form of a triangle on the coloured side. Madras to the Malay Ai'chipelago. 



1. Pseudorhombus arsius, Plate XCI, fig. 5. 



Platessa Bussellii, Gray and Hard. 111. lud. Zool. t. xciv, f. 2 ; Cantor. Catal. p. 214. 

 Mhombus letiginosus, Richards. Ami. and Mag. xi, 1843, p. 495 ; Bleeker, Pleur. p. 15. 

 Platessa chrysoptera, Richards. Ich. China, p. 278. 

 Bhombus arsius, Bleeker, Beng. en Hind. p. 76. 

 '/ Bhombus polyspilus, Bleeker, Batav. p. 203. 



Pseudorhombus Bussellii, Giinther, Catal. iv, p. 424 ; Kner, Novara Fische, p. 283 ; Day, Fish. Malabar, 

 p. 172; Bleeker, Atl. Ich. Pleuronec. p. 6, t. 233, fig. 2. 

 Pseudorhombus arsius, Giinther, 1. c. p. 426. 

 .** Pseudorhombus polyspilus, Bleeker, 1. c. p. 7, t. 237, f. 3. 



B. vii, D. 71-79, P. 11 or 12, V. 6, A. 54-61, C. 17, L. L 75-85. 



Length of head 4^ to 4|, of caudal G\, height of body 2| to 2| in the total length. iJyes— diameter 

 6 in length of head, 1 diameter irom end of snout, and closely approximating, being divided by a mere ridge. 

 Lower jaw the longer, the maxilla reaches to below the hind third of the eye. Teeth — from five to eight in the 

 lower jaw on the left side, and sis to ten on the right. Fins — dorsal fin not continuous with the 

 caudal, its longest rays are in the last third of the fin, all except the last three or four being unbi-anched, they 

 slightly project beyond the membrane : the last five anal rays branched, each fin ray has a row of small scales. 

 Pectoral two-thirds of length of head. Caudal wedge-shaped, its central rays being the longest : pre-anal spine 

 when present but slightly apparent. Scales — ctenoid on the left, cycloid on the right side : largest in 

 the posterior portion of the body : some on the maxilla. Lateral-line — smooth, its anterior curve is equal to 

 half its length, the depth between the lateral-line (just beyond its curve) and the dorsal fin equals the distance 

 from the snout to the base of the pectoral. The dorsal branch of the lateral-line goes to the base of the ninth, 

 tenth, or eleventh ray. Free portion of the tail three times as high as long. Gill-rakers 1/2 as long as 

 orbit. Colours — left side reddish-brown, usually covered with variously sized rings, and often two dark ocelli 

 on the straight portion of the lateral-line. 



Dr. Bleeker distinguishes P. Bussellii^P. arsius, as having L. 1. 85, seven to nine teeth in the left side of 

 the lower jaw, and nine to fourteen on the right : the body (in comparison with P. piohjspilus) is said to be 

 more elevated, and the profile from the neck to the dorsal more convex : teeth more numerous : whilst 

 the dorsal branch of the lateral-line commences at the eighth or ninth dorsal ray. 



P. polyspilus, L. 1. 75 to 80, five to eight teeth on both sides of the lower jaw. Head and body 

 with numerous black spots sm-rounded by blue. Dorsal branch of the lateral-line commencing below 

 the tenth dorsal ray. 



I have examined 16 specimens in my collection taken indiscriminately and with the following results : — 



; teeth 5 upper, 8 lower jaw. 



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