206 



A. Beudanti the umbilical mai-gin is represented as rounded more or 

 less broadly, and in the text which corresponds to these figures the 

 same part of the shell is nowhere stated to be angulated or carinated. 



It would thus appear that there are two forms of the species — one, 

 which may be the most typical and which for convenience has been 

 called Form A, in which the inner face of the sides is squarely trun- 

 cated, especially in the outer whorl, so that the umbilical margin is 

 rectangular; and the othej-, or Form B, in which the sides of the outer 

 whorl slope convexly down to the suture, and in which therefore the 

 umbilical mai-gin is rounded. 



The specimens from Bear Skin Bay, in Skidegate Inlet, which have 

 already been referred to Form A, correspond perfectly with Pictet's 

 figures of A. Beudanti on plate 90 of the first volume of the " Pal^on- 

 tologie Suisse." 



All the specimens of this species from Cumshewa Inlet have the 

 umbilical margin rounded, and are therefore referred to Form B. They 

 agree very well in fo]'m with most of d'Orbigny's figures of A. Beu- 

 danti, especially with figures 1 of ])lates 33 and 34 of the Atlas to the 

 first volume of the " Paleontologie Fi'an§aise, Terrains Crdtac^s." 



The Cumshewa variety of A. Beudanti occurs in great abundance in 

 large nodules of argillite. The test is beautifully preserved in these 

 nodules, but it adheres so tenaciously to the matrix that it is almost 

 invariably detached from the cast when the nodules are split open. 

 The cast is marked by distant, very flcxuous and obliquely transverse 

 constrictions or periodic arrests of growth. In the specimen figured 

 on plate 26, whose greatest diameter is about five inches and a-half, 

 there are twelve of these flexuous constrictions on the outer whorl, each 

 of which consists of a narrow but rather deep groove, which is some- 

 times partly margined by a rib-like elevation, especially on the inner 

 side of the groove and near the periphery, — and sometimes not. Small 

 portions of the test sometimes adhei-e to the cast, and such specimens 

 show that the outer surflxce of the test is faintly and rather closely 

 ribbed. The ribs are flexuous and run parallel to the distant constric- 

 tions on the cast. Near t)ie aperture of the specimen figured, the ribs 

 on a small piece of the shell which haj^pcns to be preserved are rather 

 more than one millimetre broad, but a little less than two mm. 



At Cumshewa Inlet also a cast of a very large species of Haploceras 

 was collected by Dr. Dawson, which is probably a variety of Form B. 

 of S. Beudanti. The dimensions of this specimen are as follows : — 

 maximum diameter, twenty-two inches; breadth of aperture and con- 

 sequently greatest lateral diameter of the shell, eight inches ; width of 

 umbilicus, nearly seven inches. The umbilicus has steep walls, but its 

 margin is rather rounded than angular. The outer volution is marked 



