COLUMNA. 123 



ment of the callous flange upon the columella varies a good 

 deal in apparently mature specimens. The early whorls are 

 always more or less worn in adult shells. In the young they 

 are seen to be densely decussate-granose, exactly as in Archa- 

 chatina, the initial whorl only being smoothish. Three and 

 a half whorls are dark reddish-brown; then light stripes 

 appear, and after another half whorl the adult coloration 

 sets in, the sculpture at the same time becoming rougher. 

 The broad spiral trend of the columella causes an axial hol- 

 low or ''false-umbilicus," which may be seen as a round hole 

 in a basal view of the shell. 



2. C. LEAI Tryon. PI. 46, figs. 12, 13. 



''Shell elongate-fusiform, sinistral, smooth, somewhat thick; 

 whorls 6, obliquely revolving, increasing gradually and some- 

 what convex, but broadly flattened on the periphery, which 

 in the last whorl is somewhat impressed ; apex, obtuse ; suture 

 crenate margined, not deep ; aperture small, narrow-ovate, 

 the labrum with a slight revolving white callous. Yellowish 

 with oblique zigzag longitudinal brown stripes. Length 66, 

 diam. 19 mill.; length of aperture 23, width 19 mill." 

 (Tryon) . 



Prince Island (Dr. J. Wilson, U. S. N.). 



Columna leai TRYON, Amer. Journ. Conch., ii, p. 297, pi. 

 20, f. 1. PFR., Monogr., viii, p. 252. 



Tryon 's original description and figure are given. The 

 specimens before me (fig. 12) are very similar to C. hainesi 

 Pfr., with which they agree in coloration: but they differ 

 in sculpture. Under the lens, C. leai is seen to be finely, 

 regularly plicatulate, and decussated by close spirals, similar 

 to C. columna but very much weaker, so superficial in fact 

 that the surface at first glance looks as smooth as C. hainesi. 

 The difference in size, emphasized in the original description, 

 is of small importance, and it is likely that C. hainesi and 

 leai will be found to intergrade. Specimens of leai measure : 



Length 48, diam. 15.5, aperture 18 mm. ; whorls 6%. 



Length 42, diam. 15, aperture 19.5 mm.; whorls 6V,. 



