THE NAUTILUS. 39 



Ithaca, N. Y. It is terraced, the suture being placed far below the 

 carina of the preceding whorl. The carina is unusually sharp. 

 Another specimen (fig. 4) was flat, the suture being above the carina 

 and deeply impressed. He also figures an abnormal P. thyroides 

 and P. tridentata. 



H. A. Pilsbry in MoUusca of the Southwestern States I, page 

 274, say : " Scalariform monsters are not rare, but the inception of 

 that abnormal condition seems to be invariably traceable to an in- 

 jury of the shells." He figures on plate XXIV fig. 32 a scalariform 

 specimen of Oreohelix strigosa concentrata (Dall). 



Through the kindness of the Editors of " The Nautilus " I am 

 enabled to present to its readers the following descriptions and fig- 

 ures of abnormal specimens in my cabinet. 

 Sonorella coloradoensis (Stearns). 



East side of Powell's Plateau near Mojave Creek, Grand Canyon, 

 Arizona, 1909. 



The shell is scalariform, due no doubt to an injury when young. 

 Polygyra cereolus (Miihlf). PI. V, figs. 1, 2, 3. 



Long Boat Key. Tampa Bay, Fla., 1900. 



One specimen (fig. 1) is normal up to the end of the eighth whorl. 

 A break then occurred, after which the whorl deviates downward, is 

 abruptly recurved, traversing the base across the umbilical region. 

 A nearly normal aperture is formed. In another shell, fig. 2, the 

 whorl adjacent to the aperture dips down for a short distance, sub- 

 sequently rising above the level of the spire. A well-formed nor- 

 mal example is shown in fig. 3. 



Polygyra tridentata (Say.) PI. V, figs. 10, 11. 



Wyandotte, Crawford Co., Ind., 1903. 



This shell had been broken back of the peristome, the animal in- 

 stead of repairing the break retreated eight mm., and formed a new 

 peristome and parietal tooth. 



I succeeded in extracting the animal without breaking the outer 

 peristome although the attachment to the shell was very slight, this 

 (the outer) peristome being dead. 



Polygyra tnjiecta (Say). PI. V, fig. 6. 



Jeffersonville, Clark Co., Ind., 1903. 



Peristome malformed, the callus wanting above, teeth rudi- 

 mentary. 



