260 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
ton. In 1897 the writer collected many specimens in the Potomac near Washington. 
Bean records its capture at Watermill, Long Island. 
In Fishes of North and Middle America, Jordan & Eyermann, without having 
examined and compared many specimens, assign the Lower Potomac, Albemarle 
region, and Woods Hole forms to Gunther’s Menidia gracilis, and leave the Upper 
Potomac form for Cope’s MW. beryllina, representing that fish from the fresh waters of 
the Potomac are deeper bodied. 
From an examination of a large number of specimens from the localities mentioned, 
it is found that they seem to intergrade. Specimens from Truro, Falmouth, Woods 
Hole, New Bedford, Long Island, Chesapeake Bay, Albemarle Sound, Mattamuskeet 
Lake, North Carolina, and Sampit River, South Carolina, seem to run smaller and of 
a different general appearance from the typical Potomac fish, possessing sufficient 
differences to entitle them to a subspecific name. Specimens from St. Georges 
Island, Lower Potomac, as a rule are rather more slender than those from about Wash- 
ington, otherwise they do not differ, except in average smaller size. The small size 
accounts for the slenderness, for small individuals from the vicinity of Washington 
are just as slender. 
Assuming that the numerous specimens collected in the Potomac River in the 
vicinity of Washington are Cope’s Menidia beryllina, with the description of which 
they agree very well, our studies compel us to assign the form called M. gracilis to 
this species. This seems especially justifiable, since the difference is only one of size, 
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Menidia beryllina (Cope). 
and that so slight that it is hardly of subspecific value; furthermore, Gunther’s M. 
gracilis is sine patria and his description does not fit this form better than it does 
the others. This arrangement will restrict the name M. beryllina to the Potomac 
River form. 
Redescription of Menidia beryllina. 
Length 3 inches; head 4.5; depth 5.50; eye 2.8; snout nearly 4; D. rv-i, 10; A. i, 
15; scales 39-9. Lower jaw equal to snout; spinous dorsal entirely in advance of 
origin of anal, midway between tip of snout and base of upper rudimentary rays of 
caudal; base of anal longer than head; its height in front greater than height of front 
of soft dorsal, 1.4 in head; height of soft dorsal 1.75. Color in spirits, straw; sides 
of head silvery; scales of back edged with dark dots; faint dark dots on rays of soft 
dorsal; dusky streak at base of anal; lateral silvery stripe overlying black. Specimen 
from the Potomac River, Washington, D. C., June, 1897, collected by Kendall. (U.S. 
National Museum No. 50012.) : 
Specimens from Washington present the following range of measurements: Total 
length 2.37 to 3 inches; head 4.4 to 4.5; depth 4.83 to 5.33; eye 2.6 to 3; snout 3.25 to 
3.5; D. rv to v-i, 9 to 10, mostly rv-i, 10; A. i, 16 to 18; scales 36 to 41. 
From Lower Potomac: Total length 2.5 to 2.62 inches; head 4 to 4.5; depth 5.5 to 6; 
eye 3 to 3+; D. v-i, 9 to 11, mostly v-i, 10; A. i, 15 to 18; scales 38 to 40. 
