of the Fishery Board for Scotland. 359 

 2. Soleincu. 



Eyes on right side ; ventral fins developed and free from anal. 



Species Examined. 



Genera. 



Distribution. 



S. vulgaris, . 



Solea, Quen. 



Sub-tropical and temperate 





regions of Europe. 



8. Jascaris, \ 





— kleimi, V . 







— impar, j 







S. ocellata, 







M. variegata, \ 



Microchirus, Bon. 



Mediterranean and temperate 





regions of Europe. 



M. minuta, j 







M. hispidus, . 



Monochirus, Raf. 



Mediterranean. 



S. pectoralis, . 



Synaptura, Cantor. 



Indian Ocean and Archipelago. 



P. pavoninus, 



Pardachiras, Gtr. 



Do. do. 



A. cormita, . 



A_esopia, Gtr. 



Do. do. 



L. nitidrn, 



Liachirus, Gtr. 



China Seas. 



3. Cynoglossinoi. 



Eyes on left side ; only one ventral (?) ; dorsal and anal fins confluent 

 with caudal ; termination of caudal vertebra of axial type — 

 diphy cereal. 



Species Examined. 



Genera. 



Distribution. 



0. semilwvis, . 

 P. marmorata, 

 A. lacteus, 

 A. ornata, 



Cynoglossus, Gtr. 

 Plagusia, Gtr. 

 Ammopleurops, Gtr. 

 Aphoristia, Kaup. 



China Seas. 

 East Indies. 

 Mediterranean. 



Atlantic coasts of tropical 

 America. 



It may be possible to find further structural characters which 

 differentiate these sub-families from one another, more especially the 

 Achirinse from the Soleime. The Cynoglossinse are more specialised 

 than either of these, and, in addition to their sinistral form, present 

 stages of specialisation which can be well marked off from the transitional 

 forms of the above sub-families. The confluent nature of the vertical 

 fins occurs but seldom in these sub-families — e.g., in Sdeotcdpa and 

 Synaptura. In these, however, the termination of the notochord is 

 slightly bent upwards (Soleotalpa ?) as in Solea, so that the axial 

 arrangement of the caudal vertebrae, which marks the last degree of 

 specialisation, is distinctive of the Cynoglossinfe. The other characters, 

 the total absence of the pectorals, and the presence of only one ventral, 

 are found also in the other sub-families — e.g., in Soleotalpa, Gymnachirus, 

 and certain species of Synaptura. Between the Soleinse and the 

 Achirinse there seems at present only the one differentiating character, 

 and it is of interest to note that it is the same character which forms 

 the chief means of differentiating the Pleuronectinse and the Rhombinad, 

 although it has yet to be seen whether the same difference in the internal 

 structure of the pectoral arch and ventral fins is present. 



The more specialised forms are found in the tropics, whilst the less 

 specialised range into the temperate regions of the northern hemisphere. 



