Newell.] 



474 



[Jan. 18, 



outline ovoidal and is also prolonged diagonally backward and up- 

 ward into a tube. This dorsal tube joins the shell at a sharp angle 

 and in the angle on the back are two sutures which unite about 

 half-way up the sides. The back part of this tube is oval, but on 

 the forward portion the sides are bent in and slightly recurved so 

 that in the view from above the apertures appear to have two small 

 lobes or folds pointing forward one on each side of a large median 

 lobe. 



The closed chambers increase in size uniformly. The transverse 



Vertical and lateral views X £• 



section of the smallest chamber is a narrow ovoid. Sections taken 

 above this become more and more nearly elliptical, but always a 

 little wider on the dorsal than on the ventral side of the centre. 

 The dorsi-ventral diameter of the tenth septum from the base of 

 the living chamber is one-third that of the base of the living cham- 

 ber, and is distant, measuring on the ventral angle, a little less 

 than one-half the length of the base of living chamber. 



The septa are slightly convex downward. The sutures are nearly 

 straight with no lobes nor saddles, and average about 3 mm. apart 

 at the ventral angle and 5 to 8 mm. on the dorsal side. The speci- 



