12 Proceedings of the Biological Society of Washington. 



k l . — " Head slender and pointed; gill-rakers rather 

 slender; body rather elongate, not deeply com- 

 pressed; dorsal rays, VIII, 15 "* 



Brachyistius frenatus Gill. 

 k 2 . — " Head rather deep and not pointed ; gill-rakers 

 thickish; body deep, compressed; dorsal rays X, 

 18" . . . Zalembius rosaceus Jordan and Gilbert. 

 A 2 . — Anal fin of male containing the same number rays as that of fe- 

 male ; no oval depression near its base ; front of fin without developed 

 glandular structures; the rays crowded anteriorly before a marked 

 angle in the fin, where a ray (about the twelfth) is modified into a 

 large triangular plate (represented in the female by a ray about twice 

 as wide as the others).! Teeth of jaws bluntly conic, in two series 

 (except in the lower jaw of Hyperprosopon argenteus) 



Amphistichinae, new subfamily. 

 a 1 . — Lower lip attached to chin by a broad frenum; otherwise quite 



similar to Holconotus rhodoterus . . Amphistichus argenteus Agassiz. 

 a 2 . — Lower lip without a frenum. 



6 1 . — Dorsal spine robust; the outline of the fin evenly rounded ; 

 the last spines decidedly shorter than the rays of the soft dorsal ; 

 interneurals markedly strengthened, the fourth, supporting the 

 first dorsal spine, with prominent lateral keels or wings; gill- 

 rakers rather thicker and shorter, approaching those of Amphis- 

 tichus, 15 or fewer on lower part of arch 



Holconotus rhodoterus Agassiz. 

 b 2 . — Dorsal spines rather slender, abruptly graduated to the long 

 middle spines; the last spine scarcely shorter than the soft rays; 

 anterior interneurals not markedly strengthened, the lateral ridges 

 of the fourth low and rounded; gill-rakers long and slender, 17 to 

 22 below angle. 



c 1 . — Lower jaw not so strone, little projecting, so that its teeth 

 are nearly apposed to those of the upper jaw, anal fin longer, 



of 29 to 37 rays Hyperprosopon. 



d\ — Teeth strictly biserial in both jaws; eye not so much en- 

 larged as in H. argenteus 



Hyperprosopon ( Tocichthys ) X agassizii Gill. 

 d 2 . — Inner series of teeth obsolete on sides of lower jaw; eye 

 larger than in any other species of the family 



Hyperprosopon (Hyperprosopon) argenteus Gibbons. § 

 c 2 . — Lower jaw very strong, projecting forward beyond the upper 

 at the symphysis, so that the teeth of the two jaws are not 

 nearly apposed; anal fin shorter, with about 23 rays 



Hypocritichthys analis (A. Agassiz). 



* Dorsal VIII or IX, 11 to 13; anal III, 20 to 22 (three specimens examined). 



t This is one of those interesting eases in which a secondary sexual character is not 

 confined wholly to its proper sex. 



t Tocichthys, new subgenus (subgenotype, Hyperprosopon agassizii Gill). Anal rays 

 in H. agassizii. III, 30 to 33 (six specimens). 



§ Anal rays in 31 specimens from central California, III. 30 to 35 (37 in one). 



