362 Proceedings of the Hoycd Physical Society. 



XXVIII. Notes on the British Species of Zeugopterus. By 

 George Brook, Esq., F.L.S., Lecturer on Comparative 

 Embryology in the University of Edinburgh. [Plates 

 XIV.-XVL] 



(Read 15th December 1886.) 



In the year 1835, Gottsche (1) proposed to divide the 

 species hitherto included in Klein's genus Ehombus into 

 three sections, retaining the name Bhomhis for that section 

 including the turbot and brill. His divisions were as 

 follow : 



1. Ventrals free from anal ; scales none, or small 



and cycloid, ..... Ehombu.s. 



2. Ventrals free from anal ; scales .small and 



ciliated, ..... Lei'Idorhombus. 



3. Ventrals united with anal, . , . Zeugopterus. 



The generic name Lepidorhomhus has not been adopted by 

 subsequent authors, with the exception of Glinther (2), while 

 the name Zeugopterus has been utilised by various authori- 

 ties in a different sense or discarded altogether. Yarrell (3), 

 Couch (4), Nilsson (5), and Collett (6), and some other ob- 

 servers, appear to agree in practically uniting the two genera 

 Lepidorhomhus and Zeugopterus of Gottsche into one genus, 

 for which the name Zeugopterus was retained. Steenstrup 

 (7), in 1865, pointed out that a large opening exists in the 

 interbranchial septum of K. megastoma, Donovan ; E. cardina, 

 Fries ( = Lepidorhombus norvegicus, Glinther); R punctatus, 

 Bloch ; and E. unimaculatus, Eisso. Considering this fact 

 as indicating that all these forms belong to the same genus, 

 he adopted Gottsche's nomenclature of Zeugopterus. 



Glinther, in his well-known " Catalogue," includes P. 

 megastoma and P. norvegicus in the genus Lepidorhombus ; 

 P. punctatus, having the ventrals united with the anal, 

 comes under the section Zeugopterus ; while a new genus, 

 Phrynorhombus, is suggested for the reception of P. uni- 

 maculatus. The chief distinguishing characters are : Ventrals 

 free ; no palatine or vomerine teeth ; branchiostegals, live. 



Collett includes three species — viz., megastoma, norvegie^is, 



