1904.] NATURAL SCIENCES OF PHILADELPHIA. 827 



is wholly immersed. Principal plica short. The upper palatal plica 

 is extremely short, a mere enlargement of the summit of the narrow 

 lunella, which is straight above, curved inward below. 



Length 11.2, diam. 2.3 mm.; whorls 9 (figs. 43, 44). 



Length 9, diam. 2 mm.; whorls 8J (fig. 42). 



The clausilium is parallel-sided, nearly straight, rounded at the apex, 

 excised on the columellar side of the filament. The palatal margin 

 is recurved and dilated. 



Shimo-Koshikijima, Satsuma. Types No. 87,606, A. N. S. P., from 

 No. 1,242 of Mr. Hirase's collection. 



This species is the only Zaptychoid form yet known from the Koshi- 

 kijima group. It is related to C. pinto from Tanegashima, but differs 

 in the anteriorly projecting aperture, thinner lip, less solid shell, 

 immersed subcolumellar lamella and the somewhat differently shaped 

 clausilium. Moreover, the back of the last whorl is sculptured with 

 spaced riblets, while the rest of the shell has very close, delicate striae, 

 becoming imperceptible above the middle of the shell. The largest 

 specimen (figs. 43, 44) is extensively worn, and therefore figured in 

 outline. The sculpture is well shown in fig. 42. 



Clausilia hyperaptyx n. sp. PL LVI, figs. 85, 86, 87, 88. 



The shell is fusiform, glossy, dark reddish-brown, weakly, finely 

 striate, the back of the last whorl densely and sharply striate. Upper 

 half of the spire rapidly tapering to a rather acute apex. Whorls 7J. 

 Aperture like that of C. hyperoptyx, but the peristome is somewhat 

 more widely expanded. Superior lamella continuous with the spiral 

 lamella, which penetrates to the middle of the ventral side, and is 

 much dilated within. There is no fulcrum or parallel lamella. The 

 inferior lamella recedes deeply, is high, strong and nearly straight 

 within the last whorl, and penetrates nearly as deeply as the spiral 

 lamella. The subcolumellar lamella emerges. The principal plica is 

 a half whorl long, dorsal and lateral. The upper palatal plica is short, 

 and lies mainly inward from the upper end of the lunella, with which 

 it is scarcely connected. The lunella is slightly arcuate. There are 

 no sutural plicce. 



Length 10.9, diam. 2.3 mm. 



Length 10, diam. 2 mm. 



Clausilium (PI. LVI, figs. 85, 87, 88) rather long, parallel-sided, the 

 two sides very strongly recurved (see fig. 85), the columellar side is 

 narrowly thickened ; the distal end is somewhat acuminate. 



Tokunoshima, Osumi. Types No. 87,597, A. N. S. P., from No. 

 1,230 of Mr. Hirase's collection. 



