336 Systematic Paleontology 



Occurrence. — Helderberg FoRsrATiox, New Scotland Member. 

 Miller's Spring near Cumberland. 



Collections. — ^Maryland Geological Survey, U. S. National Museum. 



Ciionetes rowei n. sp. 

 Plate LXI, Fig. 14 



Dcxcripfion. — Shell very large for Chonetes, .slightly concavo-convex, 

 and quite transverse in outline; hinge-line a little shorter than the greatest 

 width of the shell, with the cardinal angles slightly rounded ; lateral and 

 antero-lateral margins broadly rounded, front margin nearly parallel with 

 the hinge-line or slightly concave, and especially so when the ventral valve 

 has a shallow median sinus. Ventral cardinal margin with about six stout, 

 nearly vertical tubular spines on each side of the beak. Cardinal areas 

 very narrow. Surface finely striate, about twenty striae in 5 mm. along 

 the anterior margin. Width of largest example 37 mm., length 22 mm. 



This shell has a general resemblance to C. hudsonicus in form and sur- 

 face ornamentation, but its great size and flatness clearly distinguish the 

 two. Compared with C. canadensis, the largest American Chonetes (50 

 mm. or more), it is more transverse, less convex, with smaller cardinal 

 areas, and less abundant striae. 



Named for Eichard Burton Eowe, Ph. D., assistant and fellow of Johns 

 Hopkins University, who spent the summers of 1897-99 in the field, bring- 

 ing together much of the material used in this report and in his thesis 

 " The Paleodevonian formations of Maryland : a study of their strati- 

 graphy and faunas." A victim of pulmonary troubles, he died before his 

 work bore full fruitage. 



Occurrence. — Oriskany Formation, Ridgely Member. From loose 

 blocks at Miller's Spring near Cumberland, Maryland, associated with 

 Spirifer arenosus and Rensselceria {Beachia) suessana; north fork of 

 South Branch of Potomac Eiver, Pendleton County, West Virginia. 



Collections. — Maryland Geological Survey, U. S. National Museum. 



