154 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Height of body 1| times in length of head, and 4J times in total length 

 without caudal. Length of head 2| times in length of fish without caudal. 



Eye equals snout and one-fourth of head. Interorbital space equals 

 short diameter of eye (only half of short diameter in spinosus). 



Distance of spinous dorsal from tip of snout equals length of pectoral 

 (the pectoral is much shorter in spinosus). 



First si)ine of dorsal equals maxilla in length (only half as long as 

 maxilla in spinosus). Longest dorsal spine (5th) is contained 2J times 

 in length of head (4 times in spinosus). 



Pectoral reaches to origin of anal ; ventral, nearly or quite to vent. 



Maxilla extends slightly behind middle of eye ; mandible, to posterior 

 margin of eye. 



Throat and belly pure white. No spots as in trachurus. 



Hexagrammus scaber, n. (?)s. 



f Hexagammus supereiliosus (Pall.) 



In the collection of Alaskan fishes are two small individuals of the 

 genus Rexagrammus, which I cannot refer definitely to any known spe- 

 cies. They are nearest to H. supereiliosus Pallas, but, as we have none 

 of the young of this species, I must compare them with half-grown ex- 

 amples. From these and from the adult my species differs (1) in hav- 

 ing a rudimentary but quite distinct median lateral line, (2) in the 

 absence of palatine teeth, (3) in having a forked caudal, whereas super- 

 eiliosus has a distinctly rounded caudal. It may be found that a large 

 series of specimens of different ages will show a gradation into super- 

 eiliosus by the acquisition of palatine teeth, the obsolescence of the me- 

 dian lateral line, and a change in the form of the caudal ; but there is 

 nothing to base such a conclusion upon at present, and I desire to call 

 attention to the form by describing it as probably new. 



The types are numbered 23961, Amchitka, W. H. Dall, and 27920, 

 Unalashka, T. H. Bean, The first measures 2-.^^ inches and the second 

 2-n) inches to the base of the middle caudal rays. 



239G1— D. XX, 25; A. 23; V. i, 5; L. lat. about 100; 6 lateral lines. 



27920— D. XXI, 25; A. 24; V.i, 5; L. lat. about 107 ; L. transv. about 

 50; C lateral lines. 



In this description number 27920 is taken for the principal type, since, 

 being a more recent specimen, it shows the characters more clearly. 



Body oblong, moderately compressed, its depth near the origin of 

 the dorsal equals the length of the head (excluding the opercular flap) 

 and is contained 4 J times in the total length to the base of the middle 

 caudal rays; upi^er outline of head convex, but with a slight frontal de- 

 pression. The least height of the tail equals one-half the length of the 

 head, or one-ninth of the total length to base of caudal. 



The distance between the eyes is contained three times in the length 

 of the head. The snout is blunt and only two-thirds as long as the eye, 

 which is one-third as long as the head and equals the interorbital dis- 



