eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 523 



Thirty-six specimens, 19-55 mm. Lama Stop-Off. (C. M. Cat. No. 2421a-/; 

 I. U. Cat. No. 12544.) 



Head 2.6; depth 2.3; D. XVI-XVII,8-9; A. XIII,6-7; scales 25-27; eye 3.5 

 in the head, .8 in interorbital. 



Oval, the snout pointed, the premaxillary greatly protractile, the maxillary 

 reaching beyond the middle of the eye; angle and lower margin of preopercle 

 serrate, the posterior margin smooth ; ten short rakers on the lower gill-arch. 



Scales ctenoid; entire side of head to the maxillary, and top of head to between 

 the anterior margins of the eye scaled; no lateral line; anal spines depressible 

 into a scaly groove; a few scales at base of anal and caudal. Spines of dorsal and 

 anal low, the articulate rays abruptly higher. 



Variegated and variously colored, the soft dorsal, anal, and caudal hyaline. 



Family XXV. GOBIID.F. 87 



Key to the Guiana Genera of Gobiid.e. 

 a. Ventrals separate from each other; vomer without teeth. 

 b. Preopercle without spine; head naked. 



c. Scales large, less than fifty in a median series Dormitator. 



cc. Scales small, more than one hundred in a median series Guavina. 



bb. Preopercle with a downward and forward directed spine at its angle; scales moderate Eleotris. 



aa. Ventrals united, free from the abdomen. 



d. Teeth emarginate, in a single series in each jaw Evorthodus. 



dd. Teeth simple, body scaly; maxillary normal ; dorsal spines six ; interorbital area not elevated; inner edge 

 of shoulder-girdle without fleshy cirri or papillae Gobius. 88 



Dormitator Gill. 

 Prochilus Cuvier, Regne Animal, ed. 1, II, 1817, 294, preoccupied. 

 Dormitator Gill, Proc. Acad. Nat. Sci. Phila., 1862, 240. 



Type, Dormitator gundlachi Poey = Dormitator maculatus (Bloch). 



Ventrals not united ; vomer without teeth ; no spine on preopercle ; scales large ; 

 lower pharyngeals with an outer series of broad, flexible, lamelliform appendages. 



355. Dormitator gymnocephalus sp. nov. 

 Type, 18 mm. Konawaruk. (Carnegie Museum Catalog of Fishes No. 2438.) 

 Head 3.4; depth 6; D. VI ,6; A. 9; scales 26 in a median series; eye about .7 



in the snout, 3 in the head; interorbital very narrow, somewhat grooved. Skull 



smooth above. 



Mouth large, maxillary reaching to below the pupil; no teeth on the vomer; 



87 Gobius bacalaus Muller and Troschel, in Schomburgk, Reisen, III, 1848, 623 (coast of Guiana). 



88 Gobius oceanicus Pallas is recorded from the coast as G. bacalaus. 



