MICROCERION. 151 



somewhat stouter, whorls shorter. The angular lamella is 

 strongly developed. Parietal lamella much longer and 

 higher. 



Connolly (in litt.) notes that "in a series of 18 shells of 

 noltei from Klip, the largest, 3% x iy 2 mm., contains six 

 whorls and almost exactly matches Boettger's figure and de- 

 scription. The shells, however, vary in size and form, an- 

 other example, S 1 /? x 114 mm., being more conical, less cylin- 

 drical, and coming very near indeed to his figure of oblangus, 

 having, as Boettger says, more convex whorls and consequently 

 deeper suture. All these 18 specimens appear to possess the 

 two internal palatal teeth of noltei, but these are often ex- 

 tremely small and it would be easy to overlook them." 



Genus MICROCERION Ball. 



Microcerion DALL, Bull. 90, U. S. Nat Mus., 1915, p. 29, 

 type M. floridanum Dall. 



' ' Shell small, solid, few whorled, with one parietal and one 

 pillar tooth, a nodulous parietal callus uniting the lips, a 

 thickened duplex peritreme, both edges sharp, the posterior 

 sharply reflected backward, the inner or anterior projecting 

 forward, externally beveled to meet the bottom of the sinus 

 between the two lips. 



"This little shell stands about midway between Cerion 

 proper and the small Pupidae. Nothing exactly correspond- 

 ing to it is known from other formations or from the recent 

 fauna" (Dall). 



MICROCERION FLORID ANUM Dall (pi. 11, figs. 16, 17). Op. 

 cit., p. 29, pi. 1, f. 16, 17. Oligocene, Orthaulax pugnax zone, 

 Ballast Point, Tampa Bay, Florida. 



The shell is 4.75 mm. long, of about 5 whorls. The peri- 

 stome and solidity are features like Cerion, but the size, 

 shape, and small number of whorls evidently indicate more 

 affinity to Pupillida. It is perhaps a phylogerontic branch 

 of the Pupillinae, near Pupoid-es and especially Microstele, 

 which appears to stand in an ancestral relation to Pupoides. 



