Occasional Papers of the Miiseuui of Zoology ii 



has a very noticeable thickened prolongation of the outer ante- 

 rior end. The outermost 2 or 3 teeth are somewhat reduced 

 and have a larger number of cusps. On either side of the 

 center the transverse rows extend obliquely forward, but curve 

 so as to be almost transverse at their outer ends. 



Dryuuvus alhostriatus (Strebel) (1882). Twenty-seven 

 larger specimens and numerous immature ones ; from the 

 leaves of trees and brush (H, i, b; H, ii, a; H, iii, b), and also 

 (dead shellsj from the ground (H, i, a; H, iii, a). These 

 shells are very similar \n\ form to the preceding species and 

 occur with it. The coloration is always distinct. Only two 

 specimens show, around the third whorl, 3 broad, spiral bands, 

 broken by lines parallel to the growth-lines. Some of the 

 shells are quite without brown markings, and even without 

 distinct, milky-white varices, but the majority have quite dis- 

 tinct, and rather numerous, chestnut-brown varices. In addi- 

 tion, my specimens are smaller and somewhat heavier than 

 those of D. dominicns; and the spiral striations are not as dis- 

 tinct, above the greatest ventricosity of each whorl, as in tliat 

 species. The columellar reflection also appears more extensive, 

 and the umbilicus is simply a narrow slit. An example meas- 

 ures : altitude, 14.5 mm.; greater diameter, 52 (7.5 mm.). 



The jaws and radulae were examined in two specimens. 

 The radular formula (Figure i) is 135— i — 135. The rha- 

 chidian tooth is l)roader and more recurved than in the pre- 

 ceding species ; the distal end bears 3 cusps, the middle one 

 of which is larger than the others. The tooth is usually 

 twisted to one side, so as not to be exactly symmetrical. Most 

 of the lateral teeth bear 5 cusps, but some in the inner three 

 rows have only 4, while some of the outer have 6; the varia- 

 tion in the inner teeth may occur in a single longitudinal row, 



