14 University of Michigan 



■gent, as it has only the two lower spiral bands on an almost 

 white background. Young shells (2 to 3 whorls) usually have 

 flammulations above the angle and a spiral band below, but two 

 of mine lack the flammulations and I believe correspond to 

 the /r/c/»c/a-like form. 



E. Shell-shape. One shell has a distinct scalariform ten- 

 dency. This is the one mentioned above, with only two spiral 

 bands of color, and the upper of these, which is usually hidden 

 on all but the last whorl, is visible on all of the whorls, and is 

 3 mm. above the suture on the penultimate one. This shell 

 (last series of measurements) is more elongate than most speci- 

 mens of 0. longa (Pfeiffer). 



Three of the larger specimens measure: 



Altitude Greatest diameter Height aperture Diameter aperture 



62.0 mm. 56 (35 mm.) 54 (33.5 mm.) 34 (21 mm.) 



55.5 mm. 59 (33 mm.) 55 (30.5 mm.) 36 (20 mm.) 



50.5 mm. 51 (26 mm.) 50 (25.5 mm.) 32 (16 mm.) 



In two of the radulae examined from adult specimens of 

 this species the peculiar aculeate tendency of some of the inner 

 teeth is apparent (compare Pilsbry, 1902). In the youngest 

 teeth of both specimens the central tooth is of this type. In 

 one, the second lateral on the left side, and the inner three on 

 the right are of this type; while in the other the inner three on 

 the left side and the inner two on the right show this modifica- 

 tion. On the other hand, all of the older teeth, towards the 

 anterior edge of the radula, very closely approximate the nor- 

 mal, rounded form (compare Pilsbry, 1902, for Liguus). In 

 the very large radulae of 0. princeps this can be seen to be due 

 to wear (Figure 4), and the broken edges of the teeth are 

 quite apparent in the middle portion of the radula. The outer 

 teeth tend to lose the point more rapidly than do the inner, 

 and the rhachidian tooth is the last to be worn down to the 



