REPORT OF THE DIRECTOR I9IO 1 29 



from 200 feet. This region is the Scaumenac bay of the reports. 

 I have no fault to find with the determination of the age of these 

 beds as Upper Devonic; not only geological relations indicate 

 this but Doctor Eastman states that the composition of the fish 

 fauna itself substantiates this reference. There is something to 

 be said both for and against the assumption that the " Bonaven- 

 ture " conglomerate of this part of the coast is wholly Carbonic ; 

 in fact in its typical development where it fronts the gulf at 

 Perce, it certainly seems to complete the late Devonic interval. 



My attention has been attracted to a layer of loose rounded 

 boulders which underlies the fish beds along the shore not far west 

 of Migouasha landing. It is a rather striking accumulation lying 

 together like a mass of till with the boulders rolling out into the 

 landwash. These boulders, which are largely limestone, contain 

 a variety of invertebrate fossils. Some blocks consist only of 

 colonies of Halysites; another single boulder contains Dal- 

 m a n i t e s m i c r u r u s Green (head and pygidium), C a m a - 

 r o t e c h i a cf . d r y o p e Billings, a small Leptostrophia, 

 Chonetes and Pholidops and a rather striking species of Cyrto- 

 donta,^ which indicate a normal marine early Devonic fauna. The 

 boulders and their contents are comparable to the limestone 

 pebbles and boulders of the red conglomerates (Bonaventure) of 

 Perce, though the gray color and comparatively slight thickness 



^Cyrtodonta gratia — an oblique shell with very low convex valves, 

 not expanding behind, very slight forward extension, giving thus an outline 

 quite usual in the genus though perhaps somewhat less orbicular, than in the 

 few species now known in the Devonic of the Atlantic province. The 



Cyrtodonta gratia nov. Exterior of right valve and internal cast showing the 



character of teeth 



exterior is closely lined concentrically. The anterior muscle scar is deep and 

 the umbonal teeth strongly developed into a comblike arrangement in which 

 the first and third anterior teeth curve toward each other, enfolding the 

 second ; behind these six lesser teeth diminishing in size to the umbo. 



