188 



SCOMBRID^. 



the body, which it attains at about the origin of the second dorsal fin. It is 

 marked out by several of the middle striae of its scales being more raised or pro- 

 minent, or with deeper grooves between them, than the rest. 



The webs and rays of all the fins are perfectly naked or devoid of scales. 



The scales extend forwards on the nape or top of the head to a line with the 

 hinder edge of the orbit ; and on the cheeks under the eye in a band to the 

 corners of the mouth or gape : leaving a narrow space behind and underneath the 

 eye, the angle and lower border of the preopercle, the whole interopercle, the ex- 

 posed part of the lower jaw, the muzzle, and the top of the head naked appa- 

 rently, but very rough as if sanded or shagi'eened. 



Colour of the whole fish an uniform rusty or brownish black, with a slight vinous 

 tinge and glossy silken lustre : the fins darker, and all uniform. When somewhat 

 dry, the ciliated edges of the scales, and especially the caudal crests, appear 

 greyish-white or glassy (hyaline). The eye is dark and subopaline. The tongue 

 and whole inside of the mouth and gill-openings are blackish. The high-raised 

 sides of the lower jaw, as far down only as they shut within the upper jaw, are 

 pale brown : the gums and teeth are pale or white. 



The leading points in whicli the Madeiran fish differs from the Medi- 

 terranean Tetragonuriis Cuvieri, as described by MM. Cuvier and Va- 

 lenciennes, Hist. xi. 176, t. 318, are the much larger eyes, and less 

 breadth in proportion to the eyes between them at the top of the head 

 the body thicker at the shoulders, thinner at the base of the tail-fin 

 the somewhat longer head, and pectoral fins ; the higher first dorsal fin 

 the inequality of its spines ; and lastly the much greater number of the 

 teeth in the upper jaw. The exact value of these differences will be 

 best estimated from the following table : 



Diameter of eves = 



Teir. Atlanticus. 

 length of head 



3. 



whole length 



or zz 5__ 



15f. 



Space between eyes =: nearly diameter of eyes. 



Thickness of body at shoulders = ^ X depth 



T. 1 4. V c 1. •^ n whole lensrth 

 Uo. do. at base oi tau-nn ■= 2 — 



T .1 ft, 1 whole length whole length 



Length 01 head ZZ _5 =^ £__ 



4t7 » 4^ nearly. 



T ti, r J. 1 c whole length 

 Length ot pectoral fins = 2 — 



Longest (•2d.— 8th.) spines of dorsal='lHP^ll^i!^ 



3^ 

 Number of teeth in upper jaw 40 or 50 on each 



side. 

 1''. D. 15;2<'. D. 11;A. 11 ;P. Ifi ; V. 1 -H 5; 



C.7jLllIi;B.M.5. 

 7 -h VII 



Tetr. Cuvieri, Risso. 



T-.. ^ p length of head 

 Diameter oi eyes = — 2 



/■, J^^ r- \ whole length 

 or ( by the figure ) =z 2 — 



Space between eyes := 1-i x diameter of eyes.' 



Thickness of body at shoulders =: ^ X depth. 



T> J ^1, f ^ -1 n whole length 



Do. do. at ba^e ot tail-fan in 



Voh. 



Length of head = 



whole -length 



Length of pectoral fins by figure iz. — 



Longest (2"^. — ?) spines of dorsal ::= — — 



7. 



Number of teeth in upper jaw 24 or 25 on each 



side, 

 pt. D. 15 ; 2'!. D. 1 -f 13 ; A. 12 ; B. M. 5 ; 



VertsB 3'G abd.-f 22 caud. = 58 ; Cuv. and Val.f 

 pt. D. 18 ; 21. D. 1, 12 ; A. 1, 1 1 ; P. 16 ; V. 

 1, 5 ; C. 36 ; Risso. 



* This difterence however may be only due to the greater size of the eye in the Madeiran fish. 

 + These authors have omitted giving the number of rays in the pectoral, ventral, and caudal fins 

 of their fish. 



