478 REVIEW OF NORTH AMERICAN GOBIID^. 



skull above with couspicuous elevated 

 ridsjes, oue of these bouudinfr the orbit 

 above, the orbital ridges connected 

 posteriorly above by a strong cross, 

 ridge ; a sharp longitudinal ridge on 

 each side of the occipital, the two 

 nearly parallel, the post-temporals be- 

 ing attached to the posterior ends. 

 Insertions of post-temporals widely 

 separated, the distance between them 

 greater than the rather narrow inter- 

 orbital width; the post-temporal 

 bones little divergent ; top of head de- 

 pressed, both before and behind the 

 cross-ridge between eyes ; a flatfish 

 triangular area between this and 

 the little elevated supraoccipital re- 

 gion ; i»reopercle without spines ; lower 

 pharyngeals with slender depressible 

 teeth, and without lamelliform appen- 

 dages; scales of moderate size, 



ctenoid GoBiOMORUS, 2. 



dd. Vomer without teeth ; isthnui^i broad ; gill-openings scarcely extending for- 

 ward below to posterior angle of pre- 

 opercle ; skull without crests. 

 e. Body anteriorly entirely scaly. 

 /. Lower phaiyngeal teeth setaceous, the bones with an outer series of 



broad flexible lamelliform appendages 

 or teeth ; body short and elevated, 

 cyprinodontiform ; teeth slender, those 

 in the outer row scarcely larger, and 

 movable ; top of head without raised 

 crests, flatfish, its surface uneven ; 

 post-temporal bones rather strongly 

 diverging, the distance between their 

 insert ions about half the broad flattish 

 interorbital space ; no spine on preo- 

 percle or branchiostegals ; scales large, 

 ctenoid. Species herbivorous. 



DORMITATOR, 3. 



ff. Lower )di;vryngeals normal, subtriangular, the teeth stiff, villiform, none 



of them lamelliform ; scales of moder- 

 ate or small size ; body oblong or elon- 

 gate. 

 (/. Body moderately robust, the depth 4-5^ times in the length to base of 



caudal ; cranium without distinct 

 median keel; a small supraoccipital 

 crest. 

 h. Post-temporal bones little divergent, not inserted close together, the 



distance between their insertions 

 greater than the moderate interorbital 

 space, or 3J^ in length of head ; top of 

 skull little gibbous ; interorbital re- 

 gion somewhat concave or channeled ; 



