102 THE NAUTILUS. 
Barnes, and the umbonal ridge is not as well defined; the laterals 
are shorter and the shell is more transverse; the undulations cross 
the umbonal elevation instead of running parallel with it and the 
beaks are less prominent. Compared with U. mu/tiplicatus Lea our 
shell is subtriangular in outline instead of trapezoidal, always more 
winged and shorter, and the laterals are also shorter; the pos- 
terior slope is more gradual and the umbones are not flattened, and 
are more depressed than in that species, the highest point being 
nearly in the centre of the disk where there is quite a prominence ; 
the cardinals are more.depressed and the pustulations extend more 
generally over the anterior portion. 
In old specimens the sculpture diminishes almost to smoothness 
except in the superior parts, the umbonai elevation becomes obsolete 
and the shell is more elongated. Twenty specimens of all ages 
have been compared with specimens of corresponding ages of all the 
allied species, and comparisons with the type forms in the National 
Museum have been made through the kindness of Mr. Charles T. 
Simpson. 
MODIOLA PLICATULA LAMARCK—AN EXTINCT LOCALITY. 
BY R. E.C.S8 
Fifty years ago, more or less, that part of the city of Boston 
which includes the Public Garden and the grand array of fine 
avenues and streets that reach out east and west, north and south, 
and form what is locally known as the Back-Bay Section, was a 
portion of a larger territory, some six hundred acres, of wet and dry 
marsh and mud flats, that extended from Charles Street at the foot 
of “Boston Common,” to Roxbury. A considerable portion of 
this region was inhabited by a peacefully disposed and quiet com- 
munity. In numbers this community, certainly if counted, would 
have made a bigger showing than the census of human bipeds that 
constituted the population of Boston at that time. Though numer- 
ous, they were not influential and had no social status among the 
best people of “ Modern Athens.” 
This may have been owing to the fact that their ancestors did not 
come over in the Mayflower, or later with Winthrop and Salton- 
stall. No, they were here, or their forefathers were, long before the 
advent of the “ Pilgrim Fathers ;” they had an older claim, prior- 
