NOTES ON FISHES FROM THE LOWER POTOMAC RIVER. 
69 
middle of fin ; posterior to the black spot is a yellow area (white in alcoholic speci- 
mens) without spots ; the remaining part of the fin is irregularly spotted with black, 
more especially the base and extremity, leaving, in many specimens, an elongated 
space only sparingly marked with fine spots. Edges of anal and ventral fins jet black 
and of caudal and pectoral fins dusky. Females similar, larger, with fins unmarked. 
Dorsal, 10 to 12; anal, 10 or 11; head, 3J; eye, 3; depth, 3£; scales, 26 (25 to 27)-8 
(or 7). Length of mature specimens, 1£ to If inches. 146 specimens. 
8. Gambusia patruelis (Baird & Girard). Top minnow. (Plate xx.) 
Yery abundant in shallow muddy ditches and in the brackish ponds elsewhere 
alluded to, always associated with Lucania and occasionally with theFunduli and Meni- 
dice. All of the larger females taken were distended with eggs, which are relatively 
large but few in number. Specimens collected July 1 contained from 18 to 30 ova, each 
one-sixteenth of an inch in diameter, which were not in an advanced stage of incuba- 
tion. Examples obtained August 11, however, were found to contain well- developed 
embryos, which would doubtless have been extruded within a few days. Jordan* says 
the young are born in spring, which suggests that possibly two broods are raised in a 
single season. The stomach contents of one fish incidentally examined consisted 
chiefly of filamentous and unicellular algse, diatoms, amorphous vegetable matter, and 
fragments of a mosquito. 
Of the 69 specimens obtained, 68 were females, a circumstance illustrating the 
well-known relative scarcity of males. In the series collected the females have a few 
small scattered dark spots on the body and an obscure dark line along the side ; dorsal 
shows about 2 or 3 transverse rows of black spots, anal edged with black, tail irregu- 
larly spotted, the spots tending to form 2 to 4 narrow transverse bars ; usually a dark 
spot, purple in life, on side above vent; no “oblique dark band below orbit” (Jordan 
& Gilbert), although in a small proportion of the specimens there is a faint, dusky 
spot; snout with a very pronounced upward inclination. Male without purple spot on 
side, anal plain, snout less spatulate. Dorsal, 7 to 9; anal, 9 or 10; head, 3£; eye, 3; 
depth, 3f ; scales, 28 (27 to 29)-7 (or 8). Length of adult females, 1^ to If inches; of 
male, 1 inch. 
9. Anguilla anguilla (L.). “ Eel.” 
A single specimen, 4 inches long, was seined in a brackish pond inhabited by 
killifishes, silversides, etc. 
10. Tylosurus marinus (Bloch & Schneider). “ Garfish 
Examples under 8 inches in length are not infrequently seen in small companies 
around the wharves and shores. The fish move rapidly over the surface, feeding on 
small minnows and also on fragments of crabs and fish thrown into the water by line 
fishermen. This species ranges over the entire river to the limit of tide water, speci- 
mens being occasionally taken above Washington. 
11. Menidia notata (Mitchill). Silversides. 
Yery numerous, but less so than M. beryllina , with which it associates. The speci- 
mens taken varied in length from seven-eighths of an inch to 3£ inches, the average 
size being about 1J inches. The dorsal formula varied considerably, IY-I,8, IY-I,9, 
Y-I,8, Y-I,9, Y-I,10 all occurring, but Y-I,8 and V-I,9 being the most prevalent. 
* Manual of the Vertebrates. 
