1906.] FRESH-AVATER FISHES OF TiaiNIDAD. 361 



2. Two dorsal fins. ' . 



a. Anterior dorsal of 4 spines. 



a. Jaws with bands of small pointed teeth. 



28. Af/oiiostoiiius monticola. 

 (3. Jaws with minnte ciliiform teeth * ; anal tin 

 usually with III 8 raj's; 32 to 36 scales in a 

 longitudinal series. 



Second dorsal with a series of small scales behind each ray, other- 

 wise naked 29. Mugilhrasiliensis. 



Second dorsal covered with small scales 30. M. trichodon. 



h. Anterior dorsal of 7 or 8 spines ; anal with 3 spines, 

 the second and third strong f. 

 65-75 scales in a longitudinal series ; second and third anal spines 



subequal 31. Centropomus luidecimalis. 



50-60 scales in a longitudinal series ; second anal spine consider- 

 ably longer than third 32. C. ensifcrus. 



c. Anterior dorsal of 6 or 7 slender flexible spines ; 

 anal with a single feeble spine %. 

 Vomer toothed ; lower jaw projecting ; scales small. 



87. Fhilypnus dormitator. 

 Vomer toothless ; jaws equal anteriorly ; scales rather large. 



38. Dormitator maculatus. 

 B. Ventrals united to form a disc. 



1. Jaws with bands of small pointed teeth and an outer 



series of larger teeth. 



32 scales in a longitudinal series 39. Gohius fasciatus. 



60-75 scales in a longitudinal series 40. CJionophoriis banana. 



2. Teeth in the jaws in a single series 41. EvortJiodus breviceps. 



* Although only M. brasiliensis and M. tricliodon have been actually recorded 

 from Trinidad, there can be but little doubt that all the species of Mugil which occur 

 on the Atlantic coasts of America are to be obtained there. 



These may be distinguished as follows : — 



I. Second dorsal naked except for a series of small scales behind 



each ray; anal with III 8 rays (rarely III 7 or III 9). 



38 to 42 scales in a longitudinal series cephalus L. 



32 to 36 scales in a longitudinal series brasiliensis Ag. 



II. Second dorsal covered with small scales. 



A. Anal with III 9 rays (rarely III 8). 



42 to 45 scales in a longitudinal series ineilis Hancock. 



36 to 39 scales in a longitudinal series cur etna C. & V. 



B. Anal with III 8 rays (rarely HI 7 or III 9) ; 32 to 36 



scales in a longitudinal series tricliodon Poey. 



t Probably all the Atlantic species of Centropomus occur in the rivers of Trinidad. 

 They may be distinguished thus : — 



I. Anal with III 7 rays, the second and third spines subequal. 



pectinatus Poey. 



II. Anal with III 6 rays. 



A. Second and third anal spines subequal ; 65 to 75 scales 



in a longitudinal series undecimalis Bl. 



B. Second anal spine longer than third. 



75 to 90 scales in a longitudinal series parallelus Poej'. 



50 to 60 scales in a longitudinal series ensiferus Poey. 



X Allied to Fhilypnus dormitator and certainly to be found in the rivers of 

 Trinidad are two species which may be distinguished thus : — 



Vomer toothless ; lower jaw projecting ; scales small. 



Dorsal with VI, I 8 rays Meotris pisonis Gm. 



Dorsal with VII, I lOrays E. guavina C. & V. 



