356 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. X. 



Scarcely distinguishable from D. maculatus. Head 3 to 3.64; depth 

 2.86 to 3.7; D. VII-I, 8; A. I, 9; scales 34 to 37. 



Body as in D. maculatus; the snout somewhat longer and narrower, 

 comparing specimens of like size, 2.7 to 4.5 in head; mouth rather less 

 oblique, the margin of upper jaw on or below level of lower margin of 

 eye; width of mouth at its posterior angles not much longer than snout; 

 maxillary scarcely reaching vertical from anterior margin of eye, 3.15 

 to 3.55 in head; gill-rakers apparently more numerous than in D. macula- 

 tus, about 70 to 90 in anterior series on lower limb of first arch; scales 

 rather small, usually 35 in a lateral series (average for 14 specimens, 

 35.2+), ii or 12 rows between base of second dorsal and base of anal; 

 fins rather lower than in D. maculatus, ventrals failing to reach vent, 

 1.55 to 1.9 in head; pectorals scarcely reaching vertical from vent, 1.3 

 to 1.45 in head. 



Of this species 71 specimens, ranging in length from 40 to 235 mm., 

 were preserved. It was taken only in the lower courses of streams, 

 seldom far above the head of tide. It was not taken in the Rio Tuyra 

 Basin, but this is very probably due to the fact that little seining was 

 done in the lower parts of this basin. In only one place, the Rio Abaco 

 (a small stagnant, coastal stream), near Panama, was it taken in abun- 

 dance. 



Habitat: Pacific coast and rivers, from California to Ecuador. 



51. Genus Eleotris Bloch & Schneider. 



Eleotris Gronow, Zooph. Gronov., 1763, 83 (nonbinomial). 



Eleotris Bloch & Schneider, Syst. Ichth., 1801, 65 (type Gobius pisonis 



Gmelin). 



Body elongate, subcylindrical anteriorly, compressed posteriorly; 

 head low, more or less depressed above, mostly covered with scales, 

 which are usually more or less embedded; mouth rather large, oblique; 

 lower jaw projecting; preopercle with a single concealed spine at its 

 lower posterior angle; teeth small, in bands in the jaws, none on vomer; 

 gill-opening not extending forward to under eyes; scales moderate or 

 small; dorsal fins 2, well separated; caudal fin rounded; ventral fins 

 separate. 



KEY TO THE SPECIES. 



a. Scales small, 63 to 75 (most frequently 67 to 69) in lateral series, 

 about 22 rows between base of second dorsal and base of anal; 

 color bluish black above; no dark lines along rows of scales; 

 ventral surface of head and body marbled or spotted with light 

 and dark markings. picta, p. 357. 



