Maryland Geological Survey 147 



The Maryland specimens agree closely with those from the Hamilton 

 formation of oSTew York which Professor Hall first described under the 

 name of Chonetes laticosta and later referred to C. mucronatus, the origi- 

 nal description of which referred to specimens from the Marcellus shale. 

 It would be very difficult to find any difference between these specimens 

 and many of those from similar deposits of the Hamilton formation in 

 New York. On some of the specimens the comparatively long spines 

 nearly parallel to the hinge-line are nicely shown, which give the cardinal 

 angles a mucronate appearance. This species is readily distinguished by 

 its size, outline, moderate convexity, strong rounded or subangular striae, 

 and the two or three cardinal spines which curve abruptly outward par- 

 allel to the hinge-line. 



Kindle states that this is one of the most abundant species of the 

 Onondaga fauna being found nearly everywhere in it from ISTew York to 

 southwest Virginia. 



Length, 6 or 7 mm. ; width, 8 to 10 mm. 



Occurrence. — Eomney Formation, Onondaga Member. Williams 

 Eoad, 3 1/2 niiles southeast of Cumberland. Hamilton Member. Wil- 

 liams Eoad, 3I/2 miles southeast of Cumberland; east bank Evitts Creek 

 below Wolfe Mill ( ?) ; Williams Eoad 14 ™il6 east of Queen City Hotel, 

 Cumberland ; in Jennings Eun, i/o mile west of Corriganville ; Town Creek 

 Eoad at George Dief enbaugh's ; B. & 0. E. E. cut at 21st Bridge ; on Old- 

 town Eoad, east of Maryland Ave., Cumberland ; on the Hancock-Harrison- 

 ville Eoad about 2 miles north of Hancock ; McCoys Ferry ; on National 

 Eoad northeast of Cumberland; along Flintstone Creek in Gilpin; on 

 National Eoad in Gilpin west of Lock No. 56 at Great Cacapon; 14 mile 

 north of Green Spring Furnace; west of iron bridge over Town Creek 

 northeast of Oldtown; on National Eoad I/2 mile west of Licking Creek; 

 on road east of Pine Hill about 4 miles north of Oldtown ; east side Warrior 

 Mt. east of Eush; B. & 0. E. E. cut at Hancock Station, W. Va. ; on road 

 about half way between Eomney and Hanging Eock, W. Va. ; on the 

 Eomney-Hanging Eock Eoad about Y2 "lil^ north of Eomney, W. Va. ; 1 

 mile north of Eomney, W. Va. 



