1885.] NATURAL SCIENCES OF PHILADELPHIA. 67 



b. Body and head entirely scaly. 



c. Lower pharyngeal 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 scarce^ larger, and 

 movable; top ot head without raised crests, flattish, its 

 surface uneven; post-temporal bones rather strongly 

 diverging, the distance between their insertions about 

 half the broad flattish interorbital space ; no spine on 

 preopercle or branchiostegals ; scales large, ctenoid. 

 Species herbivorous. Dormitator. 2. 



cc. Lower pharyngeals normal, subtriangular, the teeth stiff, 

 villiform, none of them lamelliform ; scales of mod- 

 erate or small size ; body oblong or elongate. 

 d. Body moderately robust, the depth 4-5^ times in the 

 length to base of caudal ; cranium without distinct 

 median keel ; a small supraoccipital crest. 

 e. Post-temporal bones little divergent, not inserted 

 close together, the distance between their insertions 

 greater than the moderate interorbital space, or 3f 

 in length of head ; top of skull little gibbous ; 

 interorbital region sqmewhat concave or chan- 

 neled ; lower pharyngeals narrower than in Eleotris; 

 preopercle without spine ; scales very small, ctenoid, 

 about 100 in a longitudinal series. Vertebrae, 

 11 + 13 ; teeth moderate, the outer series enlarged. 



Guavina. 3. 

 ee. Post-temporal bones very strongly divergent, their 

 insertions close together, the distance between 

 them about § the narrow interorbital space, and 

 less than | the length of the head ; top of skull 

 somewhat elevated and declivous ; interorbital 

 area slightly convex transversely ; lower pharyn- 

 geals rather broad, the teeth bluntish ; preopercle 

 with partly concealed spine directed downward and 

 forward at its angle ; scales moderate, ctenoid, 45 

 to 60 in a longitudinal series. Vertebrae (pisonis) 

 11 + 15 ; teeth small. 1 Eleotris. 4. 



1 These characters of the skeleton are taken from Eleotris pisonis, and 

 have not been verified on other species. 



