BLOCirS TOPKNOT. 



Bloch; pi. 189. 

 Uliomhus pundatns, Yakrell; Br. Fishes, vol. ii, p. 338. 



" " Jenyns; Manual, p. 462. 



Phrynorhombus unimaculatns, Gunthek; Cat. Br. M., vol. iv. 



This species has been confounded with Mailer's Topknot, 

 from which it requires some degree of discrimination to 

 distinguish it; and even at this time a considerable amount of 

 confusion exists as regards the assignment of their synonyms, 

 as well as in the marks of distinction between them laid down 

 by different writers. We have referred to these while speaking 

 of the last-mentioned fish, and therefore it is only necessary 

 in this place to specify those characters by which it may be 

 definitely known, or which may seem to signify some difference 

 of habits. In form they nearly resemble each other, but in 

 Bloch's Topknot the width is scarcely so great; the gape is 

 more limited, and the bony structure of the jaws and face 

 less rigid; but the ridge between the eyes is a little more 

 prominent, which, however, will scarcely be discerned unless 

 the two fishes are laid side by side. The under side rough, 

 but the only unvarying mark of distinction between them 

 appears to be that in the present species the ventral fins are 

 visibly separated from the anal, whereas in Muller's Topknot 

 they are united. The colour also in Bloch's Topknot is 

 generally of a lighter cast; but we cannot perceive sufficient 

 reason for the trivial name given to it by Risso and adopted by 

 Dr. Gunther, (unimaculatus , or One-spotted,) since both these 

 species are often, and, it would appear, equally marked by a 

 defined circular spot at the side, which, however, is sometimes 

 not to be perceived. It is probable that the frequent lighter 

 colour may be ascribed to its residence on lighter ground; and 



