462 PLEURONECTID^. 



middle of the pectoral, the other further backwards ; several of the 

 anal and dorsal rays are entirely black. The left side whitish. 



23. SOLEA*. 



Solea, Monocliir, et Achu'us (Lrtcep.,s'p.), Cuv. Rkgne Anim. 

 Solea, Monocliir, Grammiclitliys, Acliirus, et Aseraggodes, Kaup in 

 Wiegm. Arch. 1855, p. 94. 



Eyes on the right side, the upper being more or less in advance of 

 the lower. Cleft of the mouth narrow, twisted round to the left side. 

 Teeth on the blind side only, where they are villiform, forming bands ; 

 no vomerine or palatine teeth. The dorsal fin commences on the 

 snout, and is not confluent with the caudal. Scales very small, 

 ctenoid ; lateral line straight. 



Inhabitants of all the temperate and tropical seas. 



Although the extreme forms of this genus show differences of ap- 

 parently sufficient importance for generic distinction, the interme- 

 diate species are so numerous, and form so gradual a transition from 

 the true Soles with the pectorals fully developed to the Achiri proper, 

 that we prefer to consider them as one genus. The following synopsis 

 will show how it may be further subdivided. 



I. The height of the body is two-fifths, or less than two-fifths, of the 



total length (without caudal). 



A. Pectorals of both sides developed. 



1. Nostrils of the blind side not dilated : Solea, p. 463. 



2. One of the nostrils of the blind side is dilated, broadly fringed : 



Pef/usa, p. 4(37. 



B. Pectorals of both sides very small : Biiglossus, p. 469. 



C. No pectoral on the blind side : Monochir, p. 470. 



D. No pectoral at all : Aseraggodes, pt., Kaup, p. 471. 



II. The height of the body is more than two-fifths of the total length 



(without caudal). 



A. Pectorals developed : Microhuglossus, p. 471. 



B. Pectorals rudimentary or absent : Achirus (Achirus, Cuv. -|- 



Aseraggodes, pt., KauV; -'r Gratnmichthgs, Kaup), p. 472. 



* 1. Solea brasiliensis, Kaup in Wiegm. Arch. 1858, p. 95. — Montevideo. 



2. angulosa, Kaup, I. c. p. 94. — Mediterranean. 



3. ovata, Cant. Catal. p. 220 (not Richards.). — Pinang. — Caudal 12|. 



4. liturata, Richards, in JVans. ZooL Soc. iii. p. 156. — Australia. 



5. Monochir punctifer, Casteln. Anim. Nouv. Poiss. p. 80. pi. 41. fig. .3 (bad). 



— Rio de Janeiro. 



6. Solea cinerea, Guichen. Explor. AJger. Poiss. p. 106. — Algeria. 



7. luctuosa, Guichen. I. c. p. 107. — .Algeria. 



8. Achirus peUucidus, Benn. Whaling Voyage, p. 277.— Pacific (open sea). 



9. - — melanospilos, Bleek. Celebes, v. p. 257. — Amboyna and Celebes. — No 



mention is made of the structure of the scales. 

 10. Heteromycteris capensis, Kaup in Wiegm. Arch. 18.')8, p. 103. 



