Conularia Missotiriensis. — Calvin. 207 
peculiar features ot drift topography are so fully exhibited. 
Winding ridges, massive domes buttressed and scored with 
ravines, flat-topped buttes with precipitous walls and reenter- 
ing angles, conical hills, dimpled plateaus, deep glens and 
secluded valleys, "soap-dishes" and kettle-holes of perfect 
symmetry, — all in the greatest profusion and variety, form a 
landscape of strange and peculiar beauty. The Mendon hills 
constitute a morainic island from the peaks of which all these 
features may be seen at a single glance. They include a clus- 
ter of five small but typical morainic lakes. "The ridge," a 
former shore line of lake Ontario, intersects the Irondequoit 
gorge two miles above its mouth and ends abruptly on the 
brink, the gap between the cut ends being one mile wide. 
Either the entire excavation of the present drift gorge has 
been accomplished since this shore line was formed, or the 
loop which it may have made around the head of the bay has 
been o-bliterated. 
NOTE ON A SPECIMEN OF CONULARIA MISSOURIENSIS 
SWALLOW, WITH CRENULATED COST^. 
By S. Calvin, Iowa City. 
A very interesting specimen of Conularia from the horizon 
of the St. Louis limestone in BroAvn county, Illinois, has late- 
ly come into my possession. This specimen agrees in nearly 
all essential particulars with the form doubtfully referred 
by Meek and Worthen (Geol. survey of 111"., Vol v, p. 541. Plate 
22 Fig. 5,) to Conularia missouriensis Swallow. I have not 
seen Swallow's type specimen, and in the absence of figures it 
is impossible to compare the specimen before me with Swal- 
low's species. There is little doubt, how^ever, that this is the 
form described by Meek and Worthen, he cif., and yet in the 
description of these authors special emphasis is placed on the 
"apparently smooth, sharp, transverse costse," and on the ap- 
parent absence of crenulations on the costa; and spaces be- 
tween. Fortunately in this new specimen a part of the surface 
is in an excellent state of preservation, and shows that in this 
remarkably large and, in the main, plainly ornamented species 
of Conularia, the sharp edges of the transverse costa> Avere very 
distinctly crenulated, the crenulations taking the form of a 
row of minute, blunt, rounded prominences along the summit 
