numerous faint spiral stria; ; spire with moderately convex outlines ; 

 apex truncate with the loss of two or two and one half whorls ; four 

 or four and one half whorls remaining, convex, with a deep suture; 

 aperture almost exactly circular; inner peritreme of old shells produced 

 to an extraordinary decree, with a few distant lamellse girdling the 

 outside; outer peritreme considerably produced, reflected a little back 

 of the plane of the aperture, slightly striated, shining; umbilicus 

 small, extending through the truncate apex- 

 Mean divergence 40° ; length .7 inch ; greatest breadth Ao inch ; 

 least breadth .37 inch. 



12. Cyclostoma mortbunduai. Shell elongate, ovate-conic ; whit- 

 ish, with a few pale brown spcts just below the suture, and often 

 with several much interrupted spiral series of the same color, with a 

 deep brownish purple summit and a lip of wax-yellow ; with closely 

 set regular rounded transverse raised lines, which are decussately 

 crenulated by numerous faint spiral stria; ; spire with moderately con- 

 vex outlines ; apex truncate with the loss of two or three whorls; four 

 whorls remaining, with a deep suture, the last a little detached from 

 the preceding near the aperture, which is ovate orbicular and sub- 

 angular above ; inner peritreme a little produced and reflected ; outer 

 peritreme moderately expanded, concave, and forming with the inner 

 one a groove, striate, subalate above, narrow on the left side ; umbili- 

 icus narrow, extending through the truncate apex. 



Mean divergence 36^ ; length ..58 inch ; greatest breadth .30 inch ; 

 least breadth .28 inch. 



13. Cyclostoma intermedium. Species intermediate between C. 

 variabik and C monstrosum. Shell sculptured and colored like the 

 pale varieties of C. variabile, with the large sutural spots less 

 distinct; whorls of less diameter than in that species but larger 

 than in C. monstrosum ; apex truncate with the loss of three whorls, 

 four remaining, quite convex, with a rather deep suture ; last whorl 

 much detached from the penult whorl ; aperture larger than in C. 

 monstrosum, with the peritremes similar, but the outer one is less ex- 

 panded. 



Mean divergence about 3S° ; length .5 inch ; greatest breadth .38 

 inch; least breadth, .27 inch. 



14. Cyclostoma monstrosum. Shell moderately elongate ; trans- 

 lucent, whitish, with unequal irregular brown spots, which are arranged 

 for the most part in transverse bands, with the largest spots just below 

 the suture; very finely decussated, but with the sculpture indistinct 

 near the aperture; spire with convex outlines; apex truncate with the 

 loss of two or three whorls ; about four and one half remaining, very 



