264 



NEW YORK STATE MUSEUM 



and does not attain a length of more than 11 mm. A peculiar 

 feature of the species is the general prevalence of a deep con- 





Chonetes nectus 



centric constriction in the ventral valve which is present in every 

 such valve yet recognized. 



The interior of the dorsal valve is highly radio-pustulate, there 

 being two strong central diverging ribs traversing the valve. 



Lower Devonic. Misery Stream, first dam in town of Sand- 

 wich; Moose river at Stony brook, Me. 



Chonetes aroostookensis nov. 



Shell transversely subrectangular, length to width as two to 

 three, hinge line straight, making almost the full width of the 

 shell; cardinal angles 90 degrees or a little more, the lateral mar- 



ch o n e t e 



roostookensis 



gins expanding gently outward for a very short distance ; lateral 

 margins direct at first then broadly curved to the anterior margin 

 which is transverse. Ventral valve gently and quite uniformly con- 

 vex, somewhat depressed to the cardinal angles. Cardinal area 



