EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 85 



A quite distinct species which I think will prove unlike any known 

 to us is a somewhat larger and elongate narrow shell carrying six or 

 seven ribs on each side. This very common form has an interior like 

 that of old individuals of S. murchisoni, the umbonal parts being 

 greatly thickened and pustulose while the m uscle scar is very deep [pi. 

 20, fig. 8-14]. Except for the fimbriate surface this species is marvel- 

 lously close in all points of structure to S. arduennensis Schnur of 

 the Coblentzian. 



Localities. Telos lake dam. Moosehead lake, 7 miles north of Kineo. 



Still another form is indicated by valves of the size of S. concinnus 

 but rather more convex [pi. 20, fig. 14]. 



Locality. Moosehead lake, just north of Soccatean point. 



Spirifer aroostookensis Clarke 



Plate 20, figure 5 

 See p. 143, pi. 30, fig. 5, 9; pi. 34, fig. 6-16 



This species is represented here only by a fragment which bears broad 

 flat plications separated by very narrow sulci, the plications being themselves 

 sometimes depressed and subsulcatc. The fold and sinus are broad and free 

 of ribs and there is no other surface sculpture save regular and faint growth 

 lines. It seems identical with the shell occurring in Aroostook county and 

 in greater abundance in the New York Oriskany. 



Locality. Tomhegan point, Moosehead lake. 



Cyrtina affinis Billings 

 Locality. Webster lake, north side. 



Chonetes impensus Clarke 



Plate 20, figure 2g 



Chonetes impensus Clarke. N. Y. State Mus. Bui. 107. 1907. p. 263 



A large shell having the aspect of Leptostrophia oriskania 

 but with coarser striae. The single specimen of this species observed is a 

 ventral valve, regularly convex, with very fine subequal striae for about one 

 half its length followed beyond a distinct growth line by much coarser striae. 

 The median stria on the early parts of the shell is larger than the rest. 

 Hinge margin cornute. Hight 21 mm, length 28 mm. Specifically unlike 

 any form known to the writer. 



Locality. Moosehead lake, 7 miles north of Kineo bay, Me. 



