DISCUSSION OF SPECIES AND THEIR DISTRIBUTION. 193 



2. Corselet developed. 



a. Palatine teeth strong ; vomer toothless; vertebra? normal Sarda 



6. Palatine teeth villiform. 



* Vomer with teeth; vertebne normal, the lower foramina small. 



Lateral line single Orycnus 



Lateral line doiilile Grammatokcynus 



* * Vomer toothless; abdominal vertebra! with the lower foramina enlarged and a portion 



between the vertebral jiroper and the ha'iiiapophyses developedin the form of a net- 

 work or trellis G vmnosauda 



II. Body very elongate, compressed. 



A. Spinous dorsal long; pectorals comparatively low; caudal not keeled; pyloric cieca rather 

 fe W. .■ Til YRSITIN.E 



1. Ventrals well developed. 



a. Fiulets present; teeth on palatines ; body in greater part naked. 



* Lateral line descending below posterior part of the spinous dorsal; body rather elongate ; 



dorsal and aual finlets G (Type, Thyrsitei iilun, South .-Vfrica and Van Diemeu's 

 Land) Th yrsites 



* * Lateral line nearly straight; dorsal fiulets 5, anal 4 ; body rather elongate. .Tiiyrsitops 



* * * Lateral line absent; finlets few; skin spinigerous; abdomen keeled; body somewhat 



elongate Ru VETTUS 



h. Finlets absent; jjalatiues toothless; scales minute. 



* Dorsal in two portions. Dagger-shaped spine behind vent Nesiauchl'S 



* * Dorsal continuous. Two lateral lines Epinnula 



2. Ventrals reduced to a single spine. 



a. Finlets present ; teeth on palatines, none on vomer. 



* Dagger-shaped spine behind vent. Body much compressed, incompletely covered with 



delicate scales Nealotvs 



* * No dagger-shaped spine. Body slender, fusiform ; lateral line descending in strongly 



oblique line below front of spinous dorsal Pkomethichthys 



b. Finlets absent ; teeth on palatines and vomer. 



* Ventral spine long, crenulate ; preoperculum spinigerous Dicrotus 



B. Body very elongate {height 18 to 20 times in length) ; spinous dorsal very long, with numerous 

 spines, continuous with the second; caudal not keeled; pyloric cieca not numerous Gkmpvun.e 



1. Body scaleless ; no palatine teeth Gempy'lus 



Subfamily SCOMBRIN^^. 



Scombrids with fusiform, moderately elongate bodies, and short (less than 12 spines) first 

 dorsal fin, separated by a wide space from the second dorsal. Pectorals high iii). Caudal 

 not carinated. 



Several of the forms in the subfamily occur at times far ont at sea, but this is no reason 

 for considering them properly pelagic. Like the counnon mackerel [Scomber seomhrus), 

 which also is found in schools remote from land, they probably all breed near the coasts, 

 and depend for their food upon the shoals of small fishes and crustaceans, which are abund- 

 ant near the land. Scomber s[n\\\'iis at. considerable depths, but probably never beyoiul 

 the lOO-fathom line. It is probaljle that many of the Scombn'dcc sink at times far below 

 the surface strata, especially in the winter. These matters are but little understood, how- 

 ever, and it is indeed probable that our knowledge of the bathic distribution of the mem- 

 bers of the mackerel family is no more imperfect than our supposed knowledge of their 

 geographic range and migrations. The remarks of Valenciennes in the "Histoire Naturclle 

 des lies Canaries " (Poissons, p. 4'J), though written fifty years ago, are worthy of consider- 

 ation today. 



Subfamily ORYCNIN^^. 



Scombrids having a fusiform, moderately elongate body, and spinous dorsal long, com- 

 posed of more than 12 spines, and contiguous to the second. Pectorals low. Caudal carinate. 

 Pyloric Cit^ca very numerous. 



The tunnies, bonitoes, and horse mackerels composing this family are even more charac- 

 teristically pelagic than those ot the preceding subfamily, but never have as yet been found 

 below 100 fiithoms. There is every reason to suppose that at times they sink below the 

 upper strata. 



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