30 THE NAUTILUS. 



A NEW NAIAD FROM NEW ZEALAND. 



BY CHARLES T. SIMPSON. 



Diplodon rvebsteri Simpson. 



Shell long, rhomboid, compressed or subcompressed, inequilateral ; 

 beaks subcompressed, pointed, their sculpture apparently a few 

 irregular lachrymose nodules arranged in a somewhat radial pattern ; 

 surface with uneven growth lines and impressed rest marks, sculp- 

 tured throughout with lachrymose nodules which are often V-shaped, 

 those along the upper part of the low posterior ridge slightly 

 knobbed ; epidei-mis dark olive green, clouded with lighter green, 

 rather dull ; pseudo-cardinals small, subcompressed, granulose, two 

 in each valve ; laterals straight, two in the left valve, one in the 

 right; muscle scars small, shallow and irregular; nacre bluish, 

 lurid purple near and in the beak cavities, thicker in front. 



Length 67, height 32, diam 14 mm. 



Length 62, height 32, diam. 17 mm. New Zealand. 



Specimens of the above were sent by Rev. William H. Webster, 

 of Wauiku, New Zealand, to the U. S. National Museum. They 

 proved to be a new species, apparently allied to the Diplodon novse- 

 hollandise Gray of Australia, but smaller, less inflated and less solid 

 than that species. In D. novce-hollandim the anterior third of the 

 shell is almost destitute of nodules ; in the present species the whole 

 surface is covered with them. These resemble somewhat those 

 found on the TJnio tuherculatiis of Barnes, but are less elevated. 

 The exact locality was not given. 



NEW AMERICAN LAND SHELLS. 



BY HENRY A. PILSBRY. 



Most of the following species were discovered by Mr. Jas. H. 

 Ferriss during a recent flying visit to the Southwest. 1 am indebted 

 to Mr. G. H. Clapp for various suggestions regarding them ; both 

 Mr. Clapp and Mr. Ferriss agreeing with me that they are new. 



Polygyra alabamensis n. sp. 



Shell depressed, about like P. vannostrandi in general contour, 



