and the Grey Mullet of the British Coast. 129 



perhaps, of any fish known ; it is composed of two oblong, 

 cylindrical bodies, slightly connected at the anterior extre- 

 mities. 



In July 1828, I, for the first time, met with a specimen of 

 the common grey mullet of the London market, and was 

 surprised to find it a non-descript species, or at least, not to 

 be the Mugil cephalus, as marked in Turton's translation of 

 the Syst. Nat. and as universally believed. Its gill-membrane, 

 or gill-flap, as more properly called by Dr. Fleming,* is six- 

 rayed, not seven, as stated in the Systema Naturae ; and 

 Cuvier's Elem. Hist. Nat. ; dorsal fins, 4, 8; pectoral, 18; 

 ventral, ^ ; anal, ^ ; caudal, 20 ; 1st dorsal at the middle of 



• I have here to acknowledge an error I had fallen into, in respect to this 

 part ; having taken the ossicles, or arched rays, for the gill-membrane, a mistake, 

 owing to the bad definition of authors, some others have committed. I had 

 inadvertently done this, by following one who has lately published a descriptive 

 enumeration, and superbly figured many of the Demerara fishes. 



*' In every species that has yet come beneath the author's observation, the 

 branchiostegous membrane has uniformly consisted of four bony rays. This 

 construction appears to be universal in the increased temperature of the tropical 

 waters, as the sea-fish have it equally with those of the rivers." See Hilhouse on 

 the Indians of Demerara — and " Ichthyology of the fresh-waters of the interior," 

 -p. 107. 



It is a misfortmie to be regretted, that we are almost as liable to embrace the 

 errors of anterior writers, as their best truths. I might have adduced from the 

 same author, on the Demerara fishes, most interesting observations respecting the 

 cobitis anableps, the viviparous siluri, their singular habits, &c. ; and of which, in 

 an unpublished ])aper on the latter genus, I have not failed to take advantage. 



It 18 not Mr. Hilhouse and myself alone who have fallen into the errors just 

 alluded to, by a misapplication of the terms, or nomenclature of ichthyologists. 

 I have found skilful anatomists here, in the same error. Had we merely been in- 

 formed that the gill-membrane forms the lower part of the operculum, or gill-cover, 

 no one could have mistaken it. 



By Willoughby and all the great ichthyologists prior to Linne, as Aldrovand, 

 Gresner, Aristotle, it was ///e»part, the ossicles or gills themselves, and not the flap 

 or cover which was so constantly alluded to as an essential part of the description — 

 and these indeed furnish a much greater variety of characteristic distinctions than 

 are obtained from a simple enumeration of rays in the gill-flap : for instance of the 

 tunny, p. 177, he says, " Branchiee. Radiosae branchiarum carunculae pectini- 

 formes exij^uje sunt et rotundse," &c. Of the shad, p. 227, " Branchiae utrinque 

 qiiatuor radiis pectinatis longis ex una tantum parte donatae ; ex altera tum globidis 

 turn aristis carent." Of the river-trout, p. 199— "trutta fluviatilis— branchiae 4, 

 prima longisismis aristis ex parte exteriore pectinata, ex interiore nuUas habet." 

 And of the smelt, p. 202, " Branchiee quaternae simplici radiorum serie pectinatae." 



It may be remarked, that the Baron Cuvier has, in some measure, revived the 

 ancient characters, and thereby rendered his method more full and satisfactory. 



The great work of ("uvier, now in progress of publication, furnishes a more 

 complete elucidation of this and otlier anatomical structures in fishes, than are to 

 be found elsewhere. 



JAN.— MARCH, 1830. K 



