INSTITUTE OF SCIENCE, PHILADELPHIA. I/I 



which may have become attached to the surface of the spire ; the anterior part of 

 the shell has the shape oi Leiorhynus, the pillar is rather thick and slightly re- 

 curved, with a moderately distinct fasciole; the canal moderately wide, shorter 

 than the pillar ; the outer lip simple, sharp, a little thickened at the resting- 

 stages, but not lirate internally ; body with a moderate callus, which at the 

 resting-stages is considerably enlarged, so that when the whorl comes to grow 

 over it (as it is not absorbed) it produces an irregularity somewhat like a 

 varix ; the whorls are ovately rounded, smooth, except for occasional trans- 

 verse undulations due to irregularities of growth, and polished; no indications 

 of color-pattern have been observed. 



The adolescent form (Figs. 5 a, 5 b) a good deal resembles a Strombns, ex- 

 cept that the anterior sulcus of the outer lip behind the canal is absent or repre- 

 sented only by the faintest wave in the margin ; the spire is entirely enveloped 

 by the backward prolongation of the last whorl, except at the tip, where the 

 envelope is usually a little eroded or defective ; there appears to be a resting- 

 stage at every two-thirds of a revolution of the whorl around the axis, for 

 which reason, looking down on the spire, the outline of the shell transverse 

 to the axis is subtriangular or three-sided ; the outer lip is simple, rather 

 sharp-edged, and very slightly, if at all, recurved ; it extends backward to the 

 tip of the spire, near which it recedes somewhat from its parallelism with the 

 axis ; at the shoulder, also, it is slightly excavated and thickened; the body is 

 smooth, with a moderate callus, which becomes thicker near the shoulder ; at 

 the shoulder, in front of the excavation above noted, it becomes very thick, 

 and is continued on to the spire parallel with the outer lip, and very near it, so 

 that between the two is a narrow, flexuous groove of considerable depth ; 

 when the shell begins to grow again the whorl is carried over this ridge, which 

 is aot absorbed, and the surface is thus rendered, as it were, varicose ; the canal 

 is short, strongly recurved, with a remarkably deep siphonal sulcus, so that 

 the end of the pillar stands forward in a marked way ; on the shoulder, half 

 way around the shell, is an ill-defined, narrow ridge, which ceases a little way 

 behind the lip. The dimensions of the figured specimen are : Lon. 68.0 ; max. 

 lat. 35.0 mm. 



The adult form differs from the adolescent by the disproportionate strength 

 of the ridge at the shoulder, by which the surface behind the ridge has become 

 flatfish as in a Cassis, but more irregular, and the width at the shoulder has 

 increased in proportion to the total length. No entirely complete specimen 

 of the adult has been found, but from the numerous fragments the proportions 

 can be approximately determined. The max. diam. is 74.0, and the length 

 about iio.o mm,, of which 15.0 mm. are behind the shoulder, while, in the 

 specimen only 68.0 mm. long, there are 17.0 mm. of length behind the 

 shoulder. 



This species appears abundantly, though in a poor state of preservation, 

 in the lower bed at Alum Bluff, and in the Chipola beds to the westward. The 



