ACANTHOPTERYGII 68/ 



characters which the examination of a large number of generic 

 types shows not to be constant. Thus the former have been 

 defined as having the praeopercular margin distinct externally, 

 the snout not projecting beyond the mouth, the nostrils of the 

 two sides on the coloured side or those of the blind side high 

 up near the dorsal line of the head ; the latter as having the 

 praeoperculum hidden under the skin, the snout projecting more 

 or less beyond the mouth, and the nasal organ of the blind side 

 similarly situated to that of the eyed side. However, the genera 

 Aphoristia and Peltorhamphus, and others among the Soles, show 

 exceptions to this definition. 1 



Principal genera : Psettodes, Atheresthes, Platysomatichthys, 

 Hippoglossus, Hippo glossoides, Hippoglossina, Poecilopsetta, Clias- 

 canopsetta, Paraliclithys, Pleuronectes, Glyptocepludus, Citharus, 

 Rhoniboidichthys, Psetta (Rhombus), Arnoglossus, Zeugopterus, 

 Lepidorhombus, Ammotretis, Rhombosolea, Solea, Achirus, Achir- 

 opsis, Soleotalpa, Synaptura, Ammopleurops, Aphoristia, Cyno- 

 glossus, Sympliurus (Plagusia). 



The following are the principal British representatives which 

 are valued as food : The Halibut (Hippoglossus vulgaris), by far 

 the largest of all Flat-Fishes, growing to a length of 1 feet or 

 more ; the Long Eough Dab (Hippoglossoides limandoides) ; the 

 Plaice (Pleuronectes platessa) ; the Flounder (P. flesus), which 

 ascends streams ; the Dab (P. limanda) ; the Smear Dab, often 

 called Lemon Sole (Glyptocephalus microcephalies) ; the Witch 

 (G. cynoglossus) ; the Megrim or Whiff (Lepidorhombus mega- 

 stoma) ; the Turbot (Psetta maxima) ; the Brill (P. laevis) ; and 

 the Sole {Solea mdgaris). 



DIVISION IV. KURTIFORMES. 



No bony stay for the praeopercle. Dorsal spines feeble, few. 

 Scapula absent, the coracoid supporting four small pterygials. 

 Ventral fins thoracic. 



Fam. 1. Kurtidae. The genus Kurtus, with a single species, 

 from the Indian and Pacific Oceans, forms an isolated, very 



1 On the morphology and classification, cf. Traquair, Tr. Linn. Soc. xxv. 1865, 

 p. 263 ; Jordan and Goss, Rep. U.S. Fish Comm.f. 1886 (1889) ; Kyle, Rep. Fish. 

 Board Scotland, 1900, p. 335. Also the Monographs of the Sole, by J. T. Cunning- 

 ham (Plymouth, 1890, 4to), and of the Plaice by Cole and Johnstone, Liverpool 

 M.B.C. Memoirs, viii. 1901. 



