172 Annals of the Carnegie Museum. 



Description. 



Shell small, patelliform, depressed conical. The highest point is 

 at the apex, which always reaches to, or overhangs the anterior margin. 

 Outline elliptical, broadest posteriorly. Beak small, slightly incurved. 

 The slope to the anterior margin is concave, the posterior slope gently 

 convex. All the specimens so far seen are casts and show no surface 

 markings other than fine concentric lines of growth. The greater 

 diameter of the aperture of an average shell is n millimeters; the 

 lesser 8 millimeters. 



Locality. — Common in the Chazy Limestone at Crown Point, Val- 

 cour Island, and Chazy, New York, and in the Aylmer Sandstone at 

 Aylmer, Canada. The specimen figured on Plate XLVI, figures i 

 and 2 is a typical form, and with it should be compared the specimen 

 from the Aylmer beds, figure 3 of the same plate. Figures 5 and 6 

 illustrate a specimen which is partially buried in the matrix. 



Archinacella ? propria Raymond. 



(Plate XLVI, figures 7-8.) 



Metoptoma montrealensis Raymond (non Billings), 1902, Bulletin 



American Paleontology, Number 14, p. 34. 

 Archinacella? propria Raymond, 1906, Annals Carnegie Museum, 



Vol. Ill, p. 575- 



This is another rather common species of the same type as Archin- 

 acella deformata (Hall) but differs from that species in the more 

 broadly elliptical outline and the position of the apex, which is nearly 

 half way between the center and the anterior margin of the shell. 



Description. 



Shell of medium size, almost circular in outline, depressed conical, 

 rising to an acute apex which is half way between the center and the 

 anterior margin. Beak small, scarcely incurved, directed forward. 

 Anterior slope concave directly under the beak but straight for the 

 greater part of the slope. Posterior slope long and slightly convex. 

 The surface shows a few very fine concentric lines. 



The greater diameter of the aperture of one specimen is 18.5 mil- 

 limeters; the lesser is 17.5 millimeters. 



Locality. — This species is fairly common in the Chazy at Crown 

 Point, Valcour Island, and Chazy, New York. The type is in the 

 Yale University Museum. 



