91: 



TABLK OF VARIATION Foil KKi IITKFX .SPECIMENS Flto.M TIIK COMMBI A 



AT UOLDEN. 



liKMAUk 



151 

 16i 

 18i 

 17i 

 15i 

 15i 



m 

 m 



16i 

 ]6i 

 164 

 15i 

 15i 

 15i- 

 16.^ 

 17* 



m 



Hi 



12-63-G 

 1(M51 ? 



1(1 55-5 



12-5'.>-? 



56 



2, 5-4, : 

 2,5-4,: 

 2, 5-4, : 

 2, 4-5. : 

 1,5-4, 



2, 4-3,': 



Female. 

 Female. 

 Female. 

 Male. 

 Foinale. 

 (?) 



Keel nil. 



Keel evident. 



Keel cvi<lont. 



Keel evident. 



Keel well marked. 



Keid well developed. 



Keel nil. 



Keel well develoiied. 



Kctd seareely evident. 



Keel evident. 



Keel evident. 

 Keel well developed. 

 Keel inoilerate. 

 Keel well developed. 

 Keel well developed . 

 Keel strong. 

 Keel strong. 



■■ Euuidistant from base of middle caudal rays and occiput (beginning of scaled rei;ion>. 



t Dorsal nearer base of middle caudal r lys than occiput. 



t Eiiuidistant from base of middle caudal rays and upper angle of preoperele. 



'■'. Eiiuidistant from base of middle caudal rays anil posterior margin of eye. 



From these tables it will be noticed that the number of dorsal rays is (juite 

 constant, being from 10 to lo. The variation in the anal is enormous, but liiis I 

 shall treat in detail. The scales are seen to vary from 1(» to 14 above the lateral 

 line; from hh to 03 along the lateral line, and from -") to 7 below the lateral llin'. 

 There is notiiing unusual in these variations, they are surpassed or eiiualled by 

 other members of the same family. The variation in the teeth is great. With 

 one exce))tion, there are two teeth in the les.ser row of the left side. The major 

 row on the left side contains 4 or .5 teeth in tlie proportion of 1 to (5. In the right 

 side 3, 4 and o teeth were found in 4, .30. and 2 specimens respectively. In the 

 lesser row of the right side 13 specimens had one tooth, 20 had 2 teeth and 1 had 

 3. Tills last specimen with dental formula 2, -5-5, 3, exceeds, the dental formula 

 of all the 17-') Atlantic slope species of this family. Among these dental formuhe 

 we tind variations, the extri'iiies of which have been taken as generic characlers. 

 The different combinations of teeth and the number of specimens having each 

 number are as follows: One with 1, ."^-4, 1 ; one with I, .")-4, 2; two with 2, 4-3, 1 ; 

 one with 2, 4-3, 2; one with 2, 4-4, 2; one with 2, 4—5, 2; one with 2, .5-3, 2. 

 eleven with 2. -5-4, 1; sixteen with 2, .5-4, 2; one with 2, 5-5, 3. The usual or 

 nominal formula is 2, -5-4, 1 or 2. The variation through ten different combina- 

 tions is excepti<ni.il. 



