MONOGRAPH OF THE GENUS STROPHIA. 
187 
naming. The general form is about that of typical S. ritchiei, but the 
aperture is wider and decidedly more open, but above all the striations 
are very numerous, thirty-four to the first whirl, and although they 
are narrow, they are so crowded as to be wider than the interspaces 
btweenthem. The color is dull white, faintly tinted with flesh color 
within. 
This Strophia may be readily known by the large size, white 
color, projecting and thin margin, with its prominent frontal bar. There 
is a superficial resemblance to S. alba, but alba has a wider, more 
flaring, margin, with the edge rolled over and sharpened, and with the 
frontal bar not at all well developed. The central tooth is also small in 
alia, and set back from the bar about twice its width. From S. grayi 
it may be distinguished as given under that heading. 
I have named this fine, large Strophia for Mr. John Ritchie, Jr., 
of Boston, the well known conchologist and scientist, who, from the 
beginning, has exhibited the utmost interest in my work upon this 
genus. 
HABITS AND DISTRIBUTION. 
Highburn Key lies to the eastward of what is known as the 
Middle Ground, an expanse of shallow water about thirty miles wide 
that stretches out toward the Atlantic from New Providence. The 
key is partly divided in two by bays which break into the land north 
and south , hence forms a rude letter H, with a rather wide cross bar. 
Both the eastern and western arm of the key are made up of 
hills, but those to the eastward are higher and a little wider, than 
those to the westward. 
We entered the bay on the south of the key and landed near its 
head. Almost immediately upon looking about I saw specimens of 
Ritchie’s Strophia. They were clinging to the stems of bushes and 
here occurred the typical form. I traced it back along the eastern 
hills northward for about a mile, a short distance beyond the ruins of 
the only building that stands on the key, and southward to the 
southern point of this division of the key, but at this point the brown 
form, No. 1, was more prevalent, growing in the shade of the thicker 
shrubbery. Westward it spreads to the front of the hills of that 
division of the key but is not found on them. Thus it has quite an 
extended range, occupying about a half of a square mile, but it is no- 
where numerous, as compared with many other species of the genus. 
