1901.] NATURAL SCIENCES OF PIIILADELnilA. 643 



It is named in honor of Dr. Arnold Jacobi, author of excellent 

 papers upon the soft anatomy of Japanese snails, the fauual rela- 

 tionships of Japan, etc. 



The specimens from Yaku-shima are more solid than those from 

 Tane-ga-ghima, and the palatal armature seems to be less devel- 

 oped, the lunella being less distinct or absent. There are three 

 palatal plicse below the principal plica, the first, second and lowest. 

 The sculpture and shape are not noticeably different, the largest 

 and smallest sent raeasuriag: 



Length 13.8, diam. 3.3 mm. 



Length 11.3, diam. 3 mm. 



Clausilia stereoma Pilsbry. PI. XXXIX, (igs. 70, 71. 



Pilsbry, these Proceedings for 1901, Vol. LIII, p. 502, with varieties 

 nugax and cognata (October 2, 19Ul). 



Shell rimate, obeselij fusiform, the spire tapering rapidly, its 

 tipper fourth venj slender; thick and e.vtre)nely strong ; olive yellow, 

 glossy; the spire distinctly striate, last two whorls smoother except 

 near the suture. Whorls about 8^, convex, the penultimate whorl 

 swollen, latter half of the last whorl compressed, tapering. 

 Aperture ovate, vertical, flesh-tinted w^thiu; peristome white, 

 reflexed and thickened within, continuous, though almost in con- 

 tact with the preceding whorl above. Superior lamella rather 

 slender, oblique, continuous with the spiral lamella. Inferior 

 lamella strong, subhorizontal, approaching the superior lamella, 

 strongly spiral within, both spiral and inferior lamellic penetrating 

 to the middle of the ventral side, Subcolumellar lamella emerg- 

 ing but not extending to the lip-edge. Principal plica very short, 

 lateral; palatal plicae four, the upper one long, converging in- 

 wardly toward the principal plica, the lower plica shorter, strong, 

 a little curved; two intermediate plicw minute, punctiform, hardly 

 perceptible. 



Length 2H, diam. G mm. 



Length 19i, diam. 5^ mm. 



Clausilium very short and broad, acuminate and thickened dis- 

 tally, very strongly arcuate (PI. XXXIX, figs. 03-65). 



Yaku-shima, Osumi, in the Northeastern Group of the Piukiu 

 Llan>ls. Types No. 81,737 Coll. A. N. S. P., from Xo. (hO of 

 Mr. Hirase's collection. 



This fine species is the most solid and strong Stereophcedma 



